Use the prefix "grpc_rb_" rather than just "grpc_".
diff --git a/src/ruby/ext/grpc/rb_call.c b/src/ruby/ext/grpc/rb_call.c
index 4658f28..466ef57 100644
--- a/src/ruby/ext/grpc/rb_call.c
+++ b/src/ruby/ext/grpc/rb_call.c
@@ -42,12 +42,13 @@
 #include "rb_completion_queue.h"
 #include "rb_grpc.h"
 
-/* grpc_sBatchResult is struct class used to hold the results of a batch call */
-static VALUE grpc_sBatchResult;
+/* grpc_rb_sBatchResult is struct class used to hold the results of a batch
+ * call. */
+static VALUE grpc_rb_sBatchResult;
 
-/* grpc_cMdAry is the MetadataArray class whose instances proxy
+/* grpc_rb_cMdAry is the MetadataArray class whose instances proxy
  * grpc_metadata_array. */
-static VALUE grpc_cMdAry;
+static VALUE grpc_rb_cMdAry;
 
 /* id_cq is the name of the hidden ivar that preserves a reference to a
  * completion queue */
@@ -70,7 +71,7 @@
  * received by the call and subsequently saved on it. */
 static ID id_status;
 
-/* sym_* are the symbol for attributes of grpc_sBatchResult. */
+/* sym_* are the symbol for attributes of grpc_rb_sBatchResult. */
 static VALUE sym_send_message;
 static VALUE sym_send_metadata;
 static VALUE sym_send_close;
@@ -126,7 +127,7 @@
   Data_Get_Struct(self, grpc_call, call);
   err = grpc_call_cancel(call);
   if (err != GRPC_CALL_OK) {
-    rb_raise(grpc_eCallError, "cancel failed: %s (code=%d)",
+    rb_raise(grpc_rb_eCallError, "cancel failed: %s (code=%d)",
              grpc_call_error_detail_of(err), err);
   }
 
@@ -148,7 +149,7 @@
 
   Saves a status object on the call.  */
 static VALUE grpc_rb_call_set_status(VALUE self, VALUE status) {
-  if (!NIL_P(status) && rb_obj_class(status) != grpc_sStatus) {
+  if (!NIL_P(status) && rb_obj_class(status) != grpc_rb_sStatus) {
     rb_raise(rb_eTypeError, "bad status: got:<%s> want: <Struct::Status>",
              rb_obj_classname(status));
     return Qnil;
@@ -257,7 +258,8 @@
 
   /* Initialize the array, compute it's capacity, then fill it. */
   grpc_metadata_array_init(md_ary);
-  md_ary_obj = Data_Wrap_Struct(grpc_cMdAry, GC_NOT_MARKED, GC_DONT_FREE, md_ary);
+  md_ary_obj =
+      Data_Wrap_Struct(grpc_rb_cMdAry, GC_NOT_MARKED, GC_DONT_FREE, md_ary);
   rb_hash_foreach(md_ary_hash, grpc_rb_md_ary_capacity_hash_cb, md_ary_obj);
   md_ary->metadata = gpr_malloc(md_ary->capacity * sizeof(grpc_metadata));
   rb_hash_foreach(md_ary_hash, grpc_rb_md_ary_fill_hash_cb, md_ary_obj);
@@ -470,8 +472,8 @@
    after the results have run */
 static VALUE grpc_run_batch_stack_build_result(run_batch_stack* st) {
   size_t i = 0;
-  VALUE result = rb_struct_new(grpc_sBatchResult, Qnil, Qnil, Qnil, Qnil, Qnil,
-                               Qnil, Qnil, Qnil, NULL);
+  VALUE result = rb_struct_new(grpc_rb_sBatchResult, Qnil, Qnil, Qnil, Qnil,
+                               Qnil, Qnil, Qnil, Qnil, NULL);
   for (i = 0; i < st->op_num; i++) {
     switch(st->ops[i].op) {
       case GRPC_OP_SEND_INITIAL_METADATA:
@@ -498,7 +500,7 @@
         rb_struct_aset(
             result,
             sym_status,
-            rb_struct_new(grpc_sStatus,
+            rb_struct_new(grpc_rb_sStatus,
                           UINT2NUM(st->recv_status),
                           (st->recv_status_details == NULL
                            ? Qnil
@@ -556,19 +558,20 @@
   err = grpc_call_start_batch(call, st.ops, st.op_num, ROBJECT(tag));
   if (err != GRPC_CALL_OK) {
     grpc_run_batch_stack_cleanup(&st);
-    rb_raise(grpc_eCallError, "grpc_call_start_batch failed with %s (code=%d)",
+    rb_raise(grpc_rb_eCallError,
+             "grpc_call_start_batch failed with %s (code=%d)",
              grpc_call_error_detail_of(err), err);
     return;
   }
   ev = grpc_rb_completion_queue_pluck_event(cqueue, tag, timeout);
   if (ev == NULL) {
     grpc_run_batch_stack_cleanup(&st);
-    rb_raise(grpc_eOutOfTime, "grpc_call_start_batch timed out");
+    rb_raise(grpc_rb_eOutOfTime, "grpc_call_start_batch timed out");
     return;
   }
   if (ev->data.op_complete != GRPC_OP_OK) {
     grpc_run_batch_stack_cleanup(&st);
-    rb_raise(grpc_eCallError, "start_batch completion failed, (code=%d)",
+    rb_raise(grpc_rb_eCallError, "start_batch completion failed, (code=%d)",
              ev->data.op_complete);
     return;
   }
@@ -579,37 +582,38 @@
   return result;
 }
 
-/* grpc_cCall is the ruby class that proxies grpc_call. */
-VALUE grpc_cCall = Qnil;
+/* grpc_rb_cCall is the ruby class that proxies grpc_call. */
+VALUE grpc_rb_cCall = Qnil;
 
-/* grpc_eCallError is the ruby class of the exception thrown during call
+/* grpc_rb_eCallError is the ruby class of the exception thrown during call
    operations; */
-VALUE grpc_eCallError = Qnil;
+VALUE grpc_rb_eCallError = Qnil;
 
-/* grpc_eOutOfTime is the ruby class of the exception thrown to indicate
+/* grpc_rb_eOutOfTime is the ruby class of the exception thrown to indicate
    a timeout. */
-VALUE grpc_eOutOfTime = Qnil;
+VALUE grpc_rb_eOutOfTime = Qnil;
 
 void Init_grpc_error_codes() {
   /* Constants representing the error codes of grpc_call_error in grpc.h */
-  VALUE grpc_mRpcErrors = rb_define_module_under(grpc_mGrpcCore, "RpcErrors");
-  rb_define_const(grpc_mRpcErrors, "OK", UINT2NUM(GRPC_CALL_OK));
-  rb_define_const(grpc_mRpcErrors, "ERROR", UINT2NUM(GRPC_CALL_ERROR));
-  rb_define_const(grpc_mRpcErrors, "NOT_ON_SERVER",
+  VALUE grpc_rb_mRpcErrors =
+      rb_define_module_under(grpc_rb_mGrpcCore, "RpcErrors");
+  rb_define_const(grpc_rb_mRpcErrors, "OK", UINT2NUM(GRPC_CALL_OK));
+  rb_define_const(grpc_rb_mRpcErrors, "ERROR", UINT2NUM(GRPC_CALL_ERROR));
+  rb_define_const(grpc_rb_mRpcErrors, "NOT_ON_SERVER",
                   UINT2NUM(GRPC_CALL_ERROR_NOT_ON_SERVER));
-  rb_define_const(grpc_mRpcErrors, "NOT_ON_CLIENT",
+  rb_define_const(grpc_rb_mRpcErrors, "NOT_ON_CLIENT",
                   UINT2NUM(GRPC_CALL_ERROR_NOT_ON_CLIENT));
-  rb_define_const(grpc_mRpcErrors, "ALREADY_ACCEPTED",
+  rb_define_const(grpc_rb_mRpcErrors, "ALREADY_ACCEPTED",
                   UINT2NUM(GRPC_CALL_ERROR_ALREADY_ACCEPTED));
-  rb_define_const(grpc_mRpcErrors, "ALREADY_INVOKED",
+  rb_define_const(grpc_rb_mRpcErrors, "ALREADY_INVOKED",
                   UINT2NUM(GRPC_CALL_ERROR_ALREADY_INVOKED));
-  rb_define_const(grpc_mRpcErrors, "NOT_INVOKED",
+  rb_define_const(grpc_rb_mRpcErrors, "NOT_INVOKED",
                   UINT2NUM(GRPC_CALL_ERROR_NOT_INVOKED));
-  rb_define_const(grpc_mRpcErrors, "ALREADY_FINISHED",
+  rb_define_const(grpc_rb_mRpcErrors, "ALREADY_FINISHED",
                   UINT2NUM(GRPC_CALL_ERROR_ALREADY_FINISHED));
-  rb_define_const(grpc_mRpcErrors, "TOO_MANY_OPERATIONS",
+  rb_define_const(grpc_rb_mRpcErrors, "TOO_MANY_OPERATIONS",
                   UINT2NUM(GRPC_CALL_ERROR_TOO_MANY_OPERATIONS));
-  rb_define_const(grpc_mRpcErrors, "INVALID_FLAGS",
+  rb_define_const(grpc_rb_mRpcErrors, "INVALID_FLAGS",
                   UINT2NUM(GRPC_CALL_ERROR_INVALID_FLAGS));
 
   /* Add the detail strings to a Hash */
@@ -637,13 +641,13 @@
                rb_str_new2("outstanding read or write present"));
   rb_hash_aset(rb_error_code_details, UINT2NUM(GRPC_CALL_ERROR_INVALID_FLAGS),
                rb_str_new2("a bad flag was given"));
-  rb_define_const(grpc_mRpcErrors, "ErrorMessages", rb_error_code_details);
+  rb_define_const(grpc_rb_mRpcErrors, "ErrorMessages", rb_error_code_details);
   rb_obj_freeze(rb_error_code_details);
 }
 
 void Init_grpc_op_codes() {
   /* Constants representing operation type codes in grpc.h */
-  VALUE rb_CallOps = rb_define_module_under(grpc_mGrpcCore, "CallOps");
+  VALUE rb_CallOps = rb_define_module_under(grpc_rb_mGrpcCore, "CallOps");
   rb_define_const(rb_CallOps, "SEND_INITIAL_METADATA",
                   UINT2NUM(GRPC_OP_SEND_INITIAL_METADATA));
   rb_define_const(rb_CallOps, "SEND_MESSAGE", UINT2NUM(GRPC_OP_SEND_MESSAGE));
@@ -663,26 +667,27 @@
 
 void Init_grpc_call() {
   /* CallError inherits from Exception to signal that it is non-recoverable */
-  grpc_eCallError =
-      rb_define_class_under(grpc_mGrpcCore, "CallError", rb_eException);
-  grpc_eOutOfTime =
-      rb_define_class_under(grpc_mGrpcCore, "OutOfTime", rb_eException);
-  grpc_cCall = rb_define_class_under(grpc_mGrpcCore, "Call", rb_cObject);
-  grpc_cMdAry = rb_define_class_under(grpc_mGrpcCore, "MetadataArray",
-                                      rb_cObject);
+  grpc_rb_eCallError =
+      rb_define_class_under(grpc_rb_mGrpcCore, "CallError", rb_eException);
+  grpc_rb_eOutOfTime =
+      rb_define_class_under(grpc_rb_mGrpcCore, "OutOfTime", rb_eException);
+  grpc_rb_cCall = rb_define_class_under(grpc_rb_mGrpcCore, "Call", rb_cObject);
+  grpc_rb_cMdAry = rb_define_class_under(grpc_rb_mGrpcCore, "MetadataArray",
+                                         rb_cObject);
 
   /* Prevent allocation or inialization of the Call class */
-  rb_define_alloc_func(grpc_cCall, grpc_rb_cannot_alloc);
-  rb_define_method(grpc_cCall, "initialize", grpc_rb_cannot_init, 0);
-  rb_define_method(grpc_cCall, "initialize_copy", grpc_rb_cannot_init_copy, 1);
+  rb_define_alloc_func(grpc_rb_cCall, grpc_rb_cannot_alloc);
+  rb_define_method(grpc_rb_cCall, "initialize", grpc_rb_cannot_init, 0);
+  rb_define_method(grpc_rb_cCall, "initialize_copy",
+                   grpc_rb_cannot_init_copy, 1);
 
   /* Add ruby analogues of the Call methods. */
-  rb_define_method(grpc_cCall, "run_batch", grpc_rb_call_run_batch, 4);
-  rb_define_method(grpc_cCall, "cancel", grpc_rb_call_cancel, 0);
-  rb_define_method(grpc_cCall, "status", grpc_rb_call_get_status, 0);
-  rb_define_method(grpc_cCall, "status=", grpc_rb_call_set_status, 1);
-  rb_define_method(grpc_cCall, "metadata", grpc_rb_call_get_metadata, 0);
-  rb_define_method(grpc_cCall, "metadata=", grpc_rb_call_set_metadata, 1);
+  rb_define_method(grpc_rb_cCall, "run_batch", grpc_rb_call_run_batch, 4);
+  rb_define_method(grpc_rb_cCall, "cancel", grpc_rb_call_cancel, 0);
+  rb_define_method(grpc_rb_cCall, "status", grpc_rb_call_get_status, 0);
+  rb_define_method(grpc_rb_cCall, "status=", grpc_rb_call_set_status, 1);
+  rb_define_method(grpc_rb_cCall, "metadata", grpc_rb_call_get_metadata, 0);
+  rb_define_method(grpc_rb_cCall, "metadata=", grpc_rb_call_set_metadata, 1);
 
   /* Ids used to support call attributes */
   id_metadata = rb_intern("metadata");
@@ -703,7 +708,7 @@
   sym_cancelled = ID2SYM(rb_intern("cancelled"));
 
   /* The Struct used to return the run_batch result. */
-  grpc_sBatchResult = rb_struct_define(
+  grpc_rb_sBatchResult = rb_struct_define(
       "BatchResult",
       "send_message",
       "send_metadata",
@@ -718,7 +723,7 @@
   /* The hash for reference counting calls, to ensure they can't be destroyed
    * more than once */
   hash_all_calls = rb_hash_new();
-  rb_define_const(grpc_cCall, "INTERNAL_ALL_CALLs", hash_all_calls);
+  rb_define_const(grpc_rb_cCall, "INTERNAL_ALL_CALLs", hash_all_calls);
 
   Init_grpc_error_codes();
   Init_grpc_op_codes();
@@ -744,5 +749,6 @@
     rb_hash_aset(hash_all_calls, OFFT2NUM((VALUE)c),
                  UINT2NUM(NUM2UINT(obj) + 1));
   }
-  return Data_Wrap_Struct(grpc_cCall, GC_NOT_MARKED, grpc_rb_call_destroy, c);
+  return Data_Wrap_Struct(grpc_rb_cCall, GC_NOT_MARKED,
+                          grpc_rb_call_destroy, c);
 }
diff --git a/src/ruby/ext/grpc/rb_call.h b/src/ruby/ext/grpc/rb_call.h
index ed4fdd5..e20a34c 100644
--- a/src/ruby/ext/grpc/rb_call.h
+++ b/src/ruby/ext/grpc/rb_call.h
@@ -49,16 +49,16 @@
 /* Converts a metadata array to a hash. */
 VALUE grpc_rb_md_ary_to_h(grpc_metadata_array *md_ary);
 
-/* grpc_cCall is the Call class whose instances proxy grpc_call. */
-extern VALUE grpc_cCall;
+/* grpc_rb_cCall is the Call class whose instances proxy grpc_call. */
+extern VALUE grpc_rb_cCall;
 
-/* grpc_eCallError is the ruby class of the exception thrown during call
+/* grpc_rb_eCallError is the ruby class of the exception thrown during call
    operations. */
-extern VALUE grpc_eCallError;
+extern VALUE grpc_rb_eCallError;
 
-/* grpc_eOutOfTime is the ruby class of the exception thrown to indicate
+/* grpc_rb_eOutOfTime is the ruby class of the exception thrown to indicate
    a timeout. */
-extern VALUE grpc_eOutOfTime;
+extern VALUE grpc_rb_eOutOfTime;
 
 /* Initializes the Call class. */
 void Init_grpc_call();
diff --git a/src/ruby/ext/grpc/rb_channel.c b/src/ruby/ext/grpc/rb_channel.c
index 215afc7..3480280 100644
--- a/src/ruby/ext/grpc/rb_channel.c
+++ b/src/ruby/ext/grpc/rb_channel.c
@@ -60,7 +60,7 @@
 
 
 /* Used during the conversion of a hash to channel args during channel setup */
-static VALUE grpc_cChannelArgs;
+static VALUE grpc_rb_cChannelArgs;
 
 /* grpc_rb_channel wraps a grpc_channel.  It provides a peer ruby object,
  * 'mark' to minimize copying when a channel is created from ruby. */
@@ -170,7 +170,7 @@
   /* Raise an error if orig is not a channel object or a subclass. */
   if (TYPE(orig) != T_DATA ||
       RDATA(orig)->dfree != (RUBY_DATA_FUNC)grpc_rb_channel_free) {
-    rb_raise(rb_eTypeError, "not a %s", rb_obj_classname(grpc_cChannel));
+    rb_raise(rb_eTypeError, "not a %s", rb_obj_classname(grpc_rb_cChannel));
     return Qnil;
   }
 
@@ -240,36 +240,38 @@
   return Qnil;
 }
 
-/* grpc_cChannel is the ruby class that proxies grpc_channel. */
-VALUE grpc_cChannel = Qnil;
+/* grpc_rb_cChannel is the ruby class that proxies grpc_channel. */
+VALUE grpc_rb_cChannel = Qnil;
 
 void Init_grpc_channel() {
-  grpc_cChannelArgs = rb_define_class("TmpChannelArgs", rb_cObject);
-  grpc_cChannel = rb_define_class_under(grpc_mGrpcCore, "Channel", rb_cObject);
+  grpc_rb_cChannelArgs = rb_define_class("TmpChannelArgs", rb_cObject);
+  grpc_rb_cChannel =
+      rb_define_class_under(grpc_rb_mGrpcCore, "Channel", rb_cObject);
 
   /* Allocates an object managed by the ruby runtime */
-  rb_define_alloc_func(grpc_cChannel, grpc_rb_channel_alloc);
+  rb_define_alloc_func(grpc_rb_cChannel, grpc_rb_channel_alloc);
 
   /* Provides a ruby constructor and support for dup/clone. */
-  rb_define_method(grpc_cChannel, "initialize", grpc_rb_channel_init, -1);
-  rb_define_method(grpc_cChannel, "initialize_copy", grpc_rb_channel_init_copy,
-                   1);
+  rb_define_method(grpc_rb_cChannel, "initialize", grpc_rb_channel_init, -1);
+  rb_define_method(grpc_rb_cChannel, "initialize_copy",
+                   grpc_rb_channel_init_copy, 1);
 
   /* Add ruby analogues of the Channel methods. */
-  rb_define_method(grpc_cChannel, "create_call", grpc_rb_channel_create_call, 4);
-  rb_define_method(grpc_cChannel, "destroy", grpc_rb_channel_destroy, 0);
-  rb_define_alias(grpc_cChannel, "close", "destroy");
+  rb_define_method(grpc_rb_cChannel, "create_call",
+                   grpc_rb_channel_create_call, 4);
+  rb_define_method(grpc_rb_cChannel, "destroy", grpc_rb_channel_destroy, 0);
+  rb_define_alias(grpc_rb_cChannel, "close", "destroy");
 
   id_channel = rb_intern("__channel");
   id_cqueue = rb_intern("__cqueue");
   id_target = rb_intern("__target");
-  rb_define_const(grpc_cChannel, "SSL_TARGET",
+  rb_define_const(grpc_rb_cChannel, "SSL_TARGET",
                   ID2SYM(rb_intern(GRPC_SSL_TARGET_NAME_OVERRIDE_ARG)));
-  rb_define_const(grpc_cChannel, "ENABLE_CENSUS",
+  rb_define_const(grpc_rb_cChannel, "ENABLE_CENSUS",
                   ID2SYM(rb_intern(GRPC_ARG_ENABLE_CENSUS)));
-  rb_define_const(grpc_cChannel, "MAX_CONCURRENT_STREAMS",
+  rb_define_const(grpc_rb_cChannel, "MAX_CONCURRENT_STREAMS",
                   ID2SYM(rb_intern(GRPC_ARG_MAX_CONCURRENT_STREAMS)));
-  rb_define_const(grpc_cChannel, "MAX_MESSAGE_LENGTH",
+  rb_define_const(grpc_rb_cChannel, "MAX_MESSAGE_LENGTH",
                   ID2SYM(rb_intern(GRPC_ARG_MAX_MESSAGE_LENGTH)));
 }
 
diff --git a/src/ruby/ext/grpc/rb_channel.h b/src/ruby/ext/grpc/rb_channel.h
index d5725ce..5c57b31 100644
--- a/src/ruby/ext/grpc/rb_channel.h
+++ b/src/ruby/ext/grpc/rb_channel.h
@@ -37,8 +37,8 @@
 #include <ruby.h>
 #include <grpc/grpc.h>
 
-/* grpc_cChannel is the Channel class whose instances proxy grpc_channel. */
-extern VALUE grpc_cChannel;
+/* grpc_rb_cChannel is the Channel class whose instances proxy grpc_channel. */
+extern VALUE grpc_rb_cChannel;
 
 /* Initializes the Channel class. */
 void Init_grpc_channel();
diff --git a/src/ruby/ext/grpc/rb_channel_args.c b/src/ruby/ext/grpc/rb_channel_args.c
index 6e486a5..9b92ec1 100644
--- a/src/ruby/ext/grpc/rb_channel_args.c
+++ b/src/ruby/ext/grpc/rb_channel_args.c
@@ -109,7 +109,7 @@
 
 static VALUE grpc_rb_hash_convert_to_channel_args0(VALUE as_value) {
   ID id_size = rb_intern("size");
-  VALUE grpc_cChannelArgs = rb_define_class("TmpChannelArgs", rb_cObject);
+  VALUE grpc_rb_cChannelArgs = rb_define_class("TmpChannelArgs", rb_cObject);
   channel_convert_params* params = (channel_convert_params*)as_value;
   size_t num_args = 0;
 
@@ -126,7 +126,7 @@
     MEMZERO(params->dst->args, grpc_arg, num_args);
     rb_hash_foreach(params->src_hash,
                     grpc_rb_channel_create_in_process_add_args_hash_cb,
-                    Data_Wrap_Struct(grpc_cChannelArgs, GC_NOT_MARKED,
+                    Data_Wrap_Struct(grpc_rb_cChannelArgs, GC_NOT_MARKED,
                                      GC_DONT_FREE, params->dst));
     /* reset num_args as grpc_rb_channel_create_in_process_add_args_hash_cb
      * decrements it during has processing */
diff --git a/src/ruby/ext/grpc/rb_completion_queue.c b/src/ruby/ext/grpc/rb_completion_queue.c
index 888744f..20ce1b9 100644
--- a/src/ruby/ext/grpc/rb_completion_queue.c
+++ b/src/ruby/ext/grpc/rb_completion_queue.c
@@ -166,25 +166,27 @@
   return next_call.event;
 }
 
-/* grpc_cCompletionQueue is the ruby class that proxies grpc_completion_queue. */
-VALUE grpc_cCompletionQueue = Qnil;
+/* grpc_rb_cCompletionQueue is the ruby class that proxies
+ * grpc_completion_queue. */
+VALUE grpc_rb_cCompletionQueue = Qnil;
 
 void Init_grpc_completion_queue() {
-  grpc_cCompletionQueue =
-      rb_define_class_under(grpc_mGrpcCore, "CompletionQueue", rb_cObject);
+  grpc_rb_cCompletionQueue =
+      rb_define_class_under(grpc_rb_mGrpcCore, "CompletionQueue", rb_cObject);
 
   /* constructor: uses an alloc func without an initializer. Using a simple
      alloc func works here as the grpc header does not specify any args for
      this func, so no separate initialization step is necessary. */
-  rb_define_alloc_func(grpc_cCompletionQueue, grpc_rb_completion_queue_alloc);
+  rb_define_alloc_func(grpc_rb_cCompletionQueue,
+                       grpc_rb_completion_queue_alloc);
 
   /* Add the next method that waits for the next event. */
-  rb_define_method(grpc_cCompletionQueue, "next", grpc_rb_completion_queue_next,
-                   1);
+  rb_define_method(grpc_rb_cCompletionQueue, "next",
+                   grpc_rb_completion_queue_next, 1);
 
   /* Add the pluck method that waits for the next event of given tag */
-  rb_define_method(grpc_cCompletionQueue, "pluck", grpc_rb_completion_queue_pluck,
-                   2);
+  rb_define_method(grpc_rb_cCompletionQueue, "pluck",
+                   grpc_rb_completion_queue_pluck, 2);
 }
 
 /* Gets the wrapped completion queue from the ruby wrapper */
diff --git a/src/ruby/ext/grpc/rb_completion_queue.h b/src/ruby/ext/grpc/rb_completion_queue.h
index 27cf6d7..1bfb80e 100644
--- a/src/ruby/ext/grpc/rb_completion_queue.h
+++ b/src/ruby/ext/grpc/rb_completion_queue.h
@@ -48,9 +48,9 @@
 grpc_event* grpc_rb_completion_queue_pluck_event(VALUE cqueue, VALUE tag,
                                                  VALUE timeout);
 
-/* grpc_cCompletionQueue is the CompletionQueue class whose instances proxy
+/* grpc_rb_cCompletionQueue is the CompletionQueue class whose instances proxy
    grpc_completion_queue. */
-extern VALUE grpc_cCompletionQueue;
+extern VALUE grpc_rb_cCompletionQueue;
 
 /* Initializes the CompletionQueue class. */
 void Init_grpc_completion_queue();
diff --git a/src/ruby/ext/grpc/rb_credentials.c b/src/ruby/ext/grpc/rb_credentials.c
index 0a8e23b..1504a48 100644
--- a/src/ruby/ext/grpc/rb_credentials.c
+++ b/src/ruby/ext/grpc/rb_credentials.c
@@ -107,7 +107,7 @@
   /* Raise an error if orig is not a credentials object or a subclass. */
   if (TYPE(orig) != T_DATA ||
       RDATA(orig)->dfree != (RUBY_DATA_FUNC)grpc_rb_credentials_free) {
-    rb_raise(rb_eTypeError, "not a %s", rb_obj_classname(grpc_cCredentials));
+    rb_raise(rb_eTypeError, "not a %s", rb_obj_classname(grpc_rb_cCredentials));
   }
 
   Data_Get_Struct(orig, grpc_rb_credentials, orig_cred);
@@ -178,7 +178,7 @@
   }
 
   wrapper->mark = Qnil;
-  return Data_Wrap_Struct(grpc_cCredentials, grpc_rb_credentials_mark,
+  return Data_Wrap_Struct(grpc_rb_cCredentials, grpc_rb_credentials_mark,
                           grpc_rb_credentials_free, wrapper);
 }
 
@@ -242,30 +242,31 @@
   return self;
 }
 
-/* grpc_cCredentials is the ruby class that proxies grpc_credentials. */
-VALUE grpc_cCredentials = Qnil;
+/* grpc_rb_cCredentials is the ruby class that proxies grpc_credentials. */
+VALUE grpc_rb_cCredentials = Qnil;
 
 void Init_grpc_credentials() {
-  grpc_cCredentials =
-      rb_define_class_under(grpc_mGrpcCore, "Credentials", rb_cObject);
+  grpc_rb_cCredentials =
+      rb_define_class_under(grpc_rb_mGrpcCore, "Credentials", rb_cObject);
 
   /* Allocates an object managed by the ruby runtime */
-  rb_define_alloc_func(grpc_cCredentials, grpc_rb_credentials_alloc);
+  rb_define_alloc_func(grpc_rb_cCredentials, grpc_rb_credentials_alloc);
 
   /* Provides a ruby constructor and support for dup/clone. */
-  rb_define_method(grpc_cCredentials, "initialize", grpc_rb_credentials_init, -1);
-  rb_define_method(grpc_cCredentials, "initialize_copy",
+  rb_define_method(grpc_rb_cCredentials, "initialize",
+                   grpc_rb_credentials_init, -1);
+  rb_define_method(grpc_rb_cCredentials, "initialize_copy",
                    grpc_rb_credentials_init_copy, 1);
 
   /* Provide static funcs that create new special instances. */
-  rb_define_singleton_method(grpc_cCredentials, "default",
+  rb_define_singleton_method(grpc_rb_cCredentials, "default",
                              grpc_rb_default_credentials_create, 0);
 
-  rb_define_singleton_method(grpc_cCredentials, "compute_engine",
+  rb_define_singleton_method(grpc_rb_cCredentials, "compute_engine",
                              grpc_rb_compute_engine_credentials_create, 0);
 
   /* Provide other methods. */
-  rb_define_method(grpc_cCredentials, "compose",
+  rb_define_method(grpc_rb_cCredentials, "compose",
                    grpc_rb_composite_credentials_create, 1);
 
   id_pem_cert_chain = rb_intern("__pem_cert_chain");
diff --git a/src/ruby/ext/grpc/rb_credentials.h b/src/ruby/ext/grpc/rb_credentials.h
index 3995065..dc0a3d0 100644
--- a/src/ruby/ext/grpc/rb_credentials.h
+++ b/src/ruby/ext/grpc/rb_credentials.h
@@ -37,9 +37,9 @@
 #include <ruby.h>
 #include <grpc/grpc_security.h>
 
-/* grpc_cCredentials is the ruby class whose instances proxy
+/* grpc_rb_cCredentials is the ruby class whose instances proxy
    grpc_credentials. */
-extern VALUE grpc_cCredentials;
+extern VALUE grpc_rb_cCredentials;
 
 /* Initializes the ruby Credentials class. */
 void Init_grpc_credentials();
diff --git a/src/ruby/ext/grpc/rb_grpc.c b/src/ruby/ext/grpc/rb_grpc.c
index 41d12ed..4f30a62 100644
--- a/src/ruby/ext/grpc/rb_grpc.c
+++ b/src/ruby/ext/grpc/rb_grpc.c
@@ -50,7 +50,7 @@
 const RUBY_DATA_FUNC GC_NOT_MARKED = NULL;
 const RUBY_DATA_FUNC GC_DONT_FREE = NULL;
 
-VALUE grpc_cTimeVal = Qnil;
+VALUE grpc_rb_cTimeVal = Qnil;
 
 /* Alloc func that blocks allocation of a given object by raising an
  * exception. */
@@ -96,7 +96,7 @@
 
   switch (TYPE(time)) {
     case T_DATA:
-      if (CLASS_OF(time) == grpc_cTimeVal) {
+      if (CLASS_OF(time) == grpc_rb_cTimeVal) {
         Data_Get_Struct(time, gpr_timespec, time_const);
         t = *time_const;
       } else if (CLASS_OF(time) == rb_cTime) {
@@ -152,35 +152,41 @@
 
 void Init_grpc_status_codes() {
   /* Constants representing the status codes or grpc_status_code in status.h */
-  VALUE grpc_mStatusCodes =
-      rb_define_module_under(grpc_mGrpcCore, "StatusCodes");
-  rb_define_const(grpc_mStatusCodes, "OK", INT2NUM(GRPC_STATUS_OK));
-  rb_define_const(grpc_mStatusCodes, "CANCELLED", INT2NUM(GRPC_STATUS_CANCELLED));
-  rb_define_const(grpc_mStatusCodes, "UNKNOWN", INT2NUM(GRPC_STATUS_UNKNOWN));
-  rb_define_const(grpc_mStatusCodes, "INVALID_ARGUMENT",
+  VALUE grpc_rb_mStatusCodes =
+      rb_define_module_under(grpc_rb_mGrpcCore, "StatusCodes");
+  rb_define_const(grpc_rb_mStatusCodes, "OK", INT2NUM(GRPC_STATUS_OK));
+  rb_define_const(grpc_rb_mStatusCodes, "CANCELLED",
+                  INT2NUM(GRPC_STATUS_CANCELLED));
+  rb_define_const(grpc_rb_mStatusCodes, "UNKNOWN",
+                  INT2NUM(GRPC_STATUS_UNKNOWN));
+  rb_define_const(grpc_rb_mStatusCodes, "INVALID_ARGUMENT",
                   INT2NUM(GRPC_STATUS_INVALID_ARGUMENT));
-  rb_define_const(grpc_mStatusCodes, "DEADLINE_EXCEEDED",
+  rb_define_const(grpc_rb_mStatusCodes, "DEADLINE_EXCEEDED",
                   INT2NUM(GRPC_STATUS_DEADLINE_EXCEEDED));
-  rb_define_const(grpc_mStatusCodes, "NOT_FOUND", INT2NUM(GRPC_STATUS_NOT_FOUND));
-  rb_define_const(grpc_mStatusCodes, "ALREADY_EXISTS",
+  rb_define_const(grpc_rb_mStatusCodes, "NOT_FOUND",
+                  INT2NUM(GRPC_STATUS_NOT_FOUND));
+  rb_define_const(grpc_rb_mStatusCodes, "ALREADY_EXISTS",
                   INT2NUM(GRPC_STATUS_ALREADY_EXISTS));
-  rb_define_const(grpc_mStatusCodes, "PERMISSION_DENIED",
+  rb_define_const(grpc_rb_mStatusCodes, "PERMISSION_DENIED",
                   INT2NUM(GRPC_STATUS_PERMISSION_DENIED));
-  rb_define_const(grpc_mStatusCodes, "UNAUTHENTICATED",
+  rb_define_const(grpc_rb_mStatusCodes, "UNAUTHENTICATED",
                   INT2NUM(GRPC_STATUS_UNAUTHENTICATED));
-  rb_define_const(grpc_mStatusCodes, "RESOURCE_EXHAUSTED",
+  rb_define_const(grpc_rb_mStatusCodes, "RESOURCE_EXHAUSTED",
                   INT2NUM(GRPC_STATUS_RESOURCE_EXHAUSTED));
-  rb_define_const(grpc_mStatusCodes, "FAILED_PRECONDITION",
+  rb_define_const(grpc_rb_mStatusCodes, "FAILED_PRECONDITION",
                   INT2NUM(GRPC_STATUS_FAILED_PRECONDITION));
-  rb_define_const(grpc_mStatusCodes, "ABORTED", INT2NUM(GRPC_STATUS_ABORTED));
-  rb_define_const(grpc_mStatusCodes, "OUT_OF_RANGE",
+  rb_define_const(grpc_rb_mStatusCodes, "ABORTED",
+                  INT2NUM(GRPC_STATUS_ABORTED));
+  rb_define_const(grpc_rb_mStatusCodes, "OUT_OF_RANGE",
                   INT2NUM(GRPC_STATUS_OUT_OF_RANGE));
-  rb_define_const(grpc_mStatusCodes, "UNIMPLEMENTED",
+  rb_define_const(grpc_rb_mStatusCodes, "UNIMPLEMENTED",
                   INT2NUM(GRPC_STATUS_UNIMPLEMENTED));
-  rb_define_const(grpc_mStatusCodes, "INTERNAL", INT2NUM(GRPC_STATUS_INTERNAL));
-  rb_define_const(grpc_mStatusCodes, "UNAVAILABLE",
+  rb_define_const(grpc_rb_mStatusCodes, "INTERNAL",
+                  INT2NUM(GRPC_STATUS_INTERNAL));
+  rb_define_const(grpc_rb_mStatusCodes, "UNAVAILABLE",
                   INT2NUM(GRPC_STATUS_UNAVAILABLE));
-  rb_define_const(grpc_mStatusCodes, "DATA_LOSS", INT2NUM(GRPC_STATUS_DATA_LOSS));
+  rb_define_const(grpc_rb_mStatusCodes, "DATA_LOSS",
+                  INT2NUM(GRPC_STATUS_DATA_LOSS));
 }
 
 /* id_at is the constructor method of the ruby standard Time class. */
@@ -212,22 +218,25 @@
 
 /* Adds a module with constants that map to gpr's static timeval structs. */
 void Init_grpc_time_consts() {
-  VALUE grpc_mTimeConsts =
-      rb_define_module_under(grpc_mGrpcCore, "TimeConsts");
-  grpc_cTimeVal =
-      rb_define_class_under(grpc_mGrpcCore, "TimeSpec", rb_cObject);
-  rb_define_const(grpc_mTimeConsts, "ZERO",
-                  Data_Wrap_Struct(grpc_cTimeVal, GC_NOT_MARKED, GC_DONT_FREE,
+  VALUE grpc_rb_mTimeConsts =
+      rb_define_module_under(grpc_rb_mGrpcCore, "TimeConsts");
+  grpc_rb_cTimeVal =
+      rb_define_class_under(grpc_rb_mGrpcCore, "TimeSpec", rb_cObject);
+  rb_define_const(grpc_rb_mTimeConsts, "ZERO",
+                  Data_Wrap_Struct(grpc_rb_cTimeVal,
+                                   GC_NOT_MARKED, GC_DONT_FREE,
                                    (void *)&gpr_time_0));
-  rb_define_const(grpc_mTimeConsts, "INFINITE_FUTURE",
-                  Data_Wrap_Struct(grpc_cTimeVal, GC_NOT_MARKED, GC_DONT_FREE,
+  rb_define_const(grpc_rb_mTimeConsts, "INFINITE_FUTURE",
+                  Data_Wrap_Struct(grpc_rb_cTimeVal,
+                                   GC_NOT_MARKED, GC_DONT_FREE,
                                    (void *)&gpr_inf_future));
-  rb_define_const(grpc_mTimeConsts, "INFINITE_PAST",
-                  Data_Wrap_Struct(grpc_cTimeVal, GC_NOT_MARKED, GC_DONT_FREE,
+  rb_define_const(grpc_rb_mTimeConsts, "INFINITE_PAST",
+                  Data_Wrap_Struct(grpc_rb_cTimeVal,
+                                   GC_NOT_MARKED, GC_DONT_FREE,
                                    (void *)&gpr_inf_past));
-  rb_define_method(grpc_cTimeVal, "to_time", grpc_rb_time_val_to_time, 0);
-  rb_define_method(grpc_cTimeVal, "inspect", grpc_rb_time_val_inspect, 0);
-  rb_define_method(grpc_cTimeVal, "to_s", grpc_rb_time_val_to_s, 0);
+  rb_define_method(grpc_rb_cTimeVal, "to_time", grpc_rb_time_val_to_time, 0);
+  rb_define_method(grpc_rb_cTimeVal, "inspect", grpc_rb_time_val_inspect, 0);
+  rb_define_method(grpc_rb_cTimeVal, "to_s", grpc_rb_time_val_to_s, 0);
   id_at = rb_intern("at");
   id_inspect = rb_intern("inspect");
   id_to_s = rb_intern("to_s");
@@ -239,23 +248,25 @@
 
 /* Initialize the GRPC module structs */
 
-/* grpc_sNewServerRpc is the struct that holds new server rpc details. */
-VALUE grpc_sNewServerRpc = Qnil;
-/* grpc_sStatus is the struct that holds status details. */
-VALUE grpc_sStatus = Qnil;
+/* grpc_rb_sNewServerRpc is the struct that holds new server rpc details. */
+VALUE grpc_rb_sNewServerRpc = Qnil;
+/* grpc_rb_sStatus is the struct that holds status details. */
+VALUE grpc_rb_sStatus = Qnil;
 
 /* Initialize the GRPC module. */
-VALUE grpc_mGRPC = Qnil;
-VALUE grpc_mGrpcCore = Qnil;
+VALUE grpc_rb_mGRPC = Qnil;
+VALUE grpc_rb_mGrpcCore = Qnil;
 
 void Init_grpc() {
   grpc_init();
   ruby_vm_at_exit(grpc_rb_shutdown);
-  grpc_mGRPC = rb_define_module("GRPC");
-  grpc_mGrpcCore = rb_define_module_under(grpc_mGRPC, "Core");
-  grpc_sNewServerRpc = rb_struct_define("NewServerRpc", "method", "host",
-                                        "deadline", "metadata", "call", NULL);
-  grpc_sStatus = rb_struct_define("Status", "code", "details", "metadata", NULL);
+  grpc_rb_mGRPC = rb_define_module("GRPC");
+  grpc_rb_mGrpcCore = rb_define_module_under(grpc_rb_mGRPC, "Core");
+  grpc_rb_sNewServerRpc =
+      rb_struct_define("NewServerRpc", "method", "host",
+                       "deadline", "metadata", "call", NULL);
+  grpc_rb_sStatus =
+      rb_struct_define("Status", "code", "details", "metadata", NULL);
   sym_code = ID2SYM(rb_intern("code"));
   sym_details = ID2SYM(rb_intern("details"));
   sym_metadata = ID2SYM(rb_intern("metadata"));
diff --git a/src/ruby/ext/grpc/rb_grpc.h b/src/ruby/ext/grpc/rb_grpc.h
index 558a1c4..3a93029 100644
--- a/src/ruby/ext/grpc/rb_grpc.h
+++ b/src/ruby/ext/grpc/rb_grpc.h
@@ -38,25 +38,25 @@
 #include <ruby.h>
 #include <grpc/support/time.h>
 
-/* grpc_mGrpcCore is the module containing the ruby wrapper GRPC classes. */
-extern VALUE grpc_mGrpcCore;
+/* grpc_rb_mGrpcCore is the module containing the ruby wrapper GRPC classes. */
+extern VALUE grpc_rb_mGrpcCore;
 
 /* Class used to wrap timeval structs. */
-extern VALUE grpc_cTimeVal;
+extern VALUE grpc_rb_cTimeVal;
 
-/* grpc_sNewServerRpc is the struct that holds new server rpc details. */
-extern VALUE grpc_sNewServerRpc;
+/* grpc_rb_sNewServerRpc is the struct that holds new server rpc details. */
+extern VALUE grpc_rb_sNewServerRpc;
 
-/* grpc_sStruct is the struct that holds status details. */
-extern VALUE grpc_sStatus;
+/* grpc_rb_sStruct is the struct that holds status details. */
+extern VALUE grpc_rb_sStatus;
 
-/* sym_code is the symbol for the code attribute of grpc_sStatus. */
+/* sym_code is the symbol for the code attribute of grpc_rb_sStatus. */
 VALUE sym_code;
 
-/* sym_details is the symbol for the details attribute of grpc_sStatus. */
+/* sym_details is the symbol for the details attribute of grpc_rb_sStatus. */
 VALUE sym_details;
 
-/* sym_metadata is the symbol for the metadata attribute of grpc_sStatus. */
+/* sym_metadata is the symbol for the metadata attribute of grpc_rb_sStatus. */
 VALUE sym_metadata;
 
 /* GC_NOT_MARKED is used in calls to Data_Wrap_Struct to indicate that the
diff --git a/src/ruby/ext/grpc/rb_server.c b/src/ruby/ext/grpc/rb_server.c
index c81906b..33d9d69 100644
--- a/src/ruby/ext/grpc/rb_server.c
+++ b/src/ruby/ext/grpc/rb_server.c
@@ -43,8 +43,8 @@
 #include "rb_server_credentials.h"
 #include "rb_grpc.h"
 
-/* grpc_cServer is the ruby class that proxies grpc_server. */
-VALUE grpc_cServer = Qnil;
+/* grpc_rb_cServer is the ruby class that proxies grpc_server. */
+VALUE grpc_rb_cServer = Qnil;
 
 /* id_at is the constructor method of the ruby standard Time class. */
 static ID id_at;
@@ -143,7 +143,7 @@
   /* Raise an error if orig is not a server object or a subclass. */
   if (TYPE(orig) != T_DATA ||
       RDATA(orig)->dfree != (RUBY_DATA_FUNC)grpc_rb_server_free) {
-    rb_raise(rb_eTypeError, "not a %s", rb_obj_classname(grpc_cServer));
+    rb_raise(rb_eTypeError, "not a %s", rb_obj_classname(grpc_rb_cServer));
   }
 
   Data_Get_Struct(orig, grpc_rb_server, orig_srv);
@@ -208,7 +208,8 @@
         ROBJECT(tag_new));
     if (err != GRPC_CALL_OK) {
       grpc_request_call_stack_cleanup(&st);
-      rb_raise(grpc_eCallError, "grpc_server_request_call failed: %s (code=%d)",
+      rb_raise(grpc_rb_eCallError,
+              "grpc_server_request_call failed: %s (code=%d)",
                grpc_call_error_detail_of(err), err);
       return Qnil;
     }
@@ -220,14 +221,14 @@
     if (ev->data.op_complete != GRPC_OP_OK) {
       grpc_request_call_stack_cleanup(&st);
       grpc_event_finish(ev);
-      rb_raise(grpc_eCallError, "request_call completion failed: (code=%d)",
+      rb_raise(grpc_rb_eCallError, "request_call completion failed: (code=%d)",
                ev->data.op_complete);
       return Qnil;
     }
 
     /* build the NewServerRpc struct result */
     result = rb_struct_new(
-        grpc_sNewServerRpc,
+        grpc_rb_sNewServerRpc,
         rb_str_new2(st.details.method),
         rb_str_new2(st.details.host),
         rb_funcall(rb_cTime, id_at, 2, INT2NUM(st.details.deadline.tv_sec),
@@ -313,21 +314,25 @@
 }
 
 void Init_grpc_server() {
-  grpc_cServer = rb_define_class_under(grpc_mGrpcCore, "Server", rb_cObject);
+  grpc_rb_cServer =
+      rb_define_class_under(grpc_rb_mGrpcCore, "Server", rb_cObject);
 
   /* Allocates an object managed by the ruby runtime */
-  rb_define_alloc_func(grpc_cServer, grpc_rb_server_alloc);
+  rb_define_alloc_func(grpc_rb_cServer, grpc_rb_server_alloc);
 
   /* Provides a ruby constructor and support for dup/clone. */
-  rb_define_method(grpc_cServer, "initialize", grpc_rb_server_init, 2);
-  rb_define_method(grpc_cServer, "initialize_copy", grpc_rb_server_init_copy, 1);
+  rb_define_method(grpc_rb_cServer, "initialize", grpc_rb_server_init, 2);
+  rb_define_method(grpc_rb_cServer, "initialize_copy",
+                   grpc_rb_server_init_copy, 1);
 
   /* Add the server methods. */
-  rb_define_method(grpc_cServer, "request_call", grpc_rb_server_request_call, 3);
-  rb_define_method(grpc_cServer, "start", grpc_rb_server_start, 0);
-  rb_define_method(grpc_cServer, "destroy", grpc_rb_server_destroy, 0);
-  rb_define_alias(grpc_cServer, "close", "destroy");
-  rb_define_method(grpc_cServer, "add_http2_port", grpc_rb_server_add_http2_port,
+  rb_define_method(grpc_rb_cServer, "request_call",
+                   grpc_rb_server_request_call, 3);
+  rb_define_method(grpc_rb_cServer, "start", grpc_rb_server_start, 0);
+  rb_define_method(grpc_rb_cServer, "destroy", grpc_rb_server_destroy, 0);
+  rb_define_alias(grpc_rb_cServer, "close", "destroy");
+  rb_define_method(grpc_rb_cServer, "add_http2_port",
+                   grpc_rb_server_add_http2_port,
                    -1);
   id_at = rb_intern("at");
 }
diff --git a/src/ruby/ext/grpc/rb_server.h b/src/ruby/ext/grpc/rb_server.h
index 8bd4f44..22e88a7 100644
--- a/src/ruby/ext/grpc/rb_server.h
+++ b/src/ruby/ext/grpc/rb_server.h
@@ -37,9 +37,9 @@
 #include <ruby.h>
 #include <grpc/grpc.h>
 
-/* grpc_cServer is the Server class whose instances proxy
+/* grpc_rb_cServer is the Server class whose instances proxy
    grpc_byte_buffer. */
-extern VALUE grpc_cServer;
+extern VALUE grpc_rb_cServer;
 
 /* Initializes the Server class. */
 void Init_grpc_server();
diff --git a/src/ruby/ext/grpc/rb_server_credentials.c b/src/ruby/ext/grpc/rb_server_credentials.c
index bdeb93d..8b813ea 100644
--- a/src/ruby/ext/grpc/rb_server_credentials.c
+++ b/src/ruby/ext/grpc/rb_server_credentials.c
@@ -109,7 +109,7 @@
   if (TYPE(orig) != T_DATA ||
       RDATA(orig)->dfree != (RUBY_DATA_FUNC)grpc_rb_server_credentials_free) {
     rb_raise(rb_eTypeError, "not a %s",
-             rb_obj_classname(grpc_cServerCredentials));
+             rb_obj_classname(grpc_rb_cServerCredentials));
   }
 
   Data_Get_Struct(orig, grpc_rb_server_credentials, orig_ch);
@@ -180,21 +180,22 @@
   return self;
 }
 
-/* grpc_cServerCredentials is the ruby class that proxies
+/* grpc_rb_cServerCredentials is the ruby class that proxies
    grpc_server_credentials. */
-VALUE grpc_cServerCredentials = Qnil;
+VALUE grpc_rb_cServerCredentials = Qnil;
 
 void Init_grpc_server_credentials() {
-  grpc_cServerCredentials =
-      rb_define_class_under(grpc_mGrpcCore, "ServerCredentials", rb_cObject);
+  grpc_rb_cServerCredentials =
+      rb_define_class_under(grpc_rb_mGrpcCore, "ServerCredentials", rb_cObject);
 
   /* Allocates an object managed by the ruby runtime */
-  rb_define_alloc_func(grpc_cServerCredentials, grpc_rb_server_credentials_alloc);
+  rb_define_alloc_func(grpc_rb_cServerCredentials,
+                       grpc_rb_server_credentials_alloc);
 
   /* Provides a ruby constructor and support for dup/clone. */
-  rb_define_method(grpc_cServerCredentials, "initialize",
+  rb_define_method(grpc_rb_cServerCredentials, "initialize",
                    grpc_rb_server_credentials_init, 3);
-  rb_define_method(grpc_cServerCredentials, "initialize_copy",
+  rb_define_method(grpc_rb_cServerCredentials, "initialize_copy",
                    grpc_rb_server_credentials_init_copy, 1);
 
   id_pem_cert_chain = rb_intern("__pem_cert_chain");
diff --git a/src/ruby/ext/grpc/rb_server_credentials.h b/src/ruby/ext/grpc/rb_server_credentials.h
index bca6e28..f79a869 100644
--- a/src/ruby/ext/grpc/rb_server_credentials.h
+++ b/src/ruby/ext/grpc/rb_server_credentials.h
@@ -37,9 +37,9 @@
 #include <ruby.h>
 #include <grpc/grpc_security.h>
 
-/* grpc_cServerCredentials is the ruby class whose instances proxy
+/* grpc_rb_cServerCredentials is the ruby class whose instances proxy
    grpc_server_credentials. */
-extern VALUE grpc_cServerCredentials;
+extern VALUE grpc_rb_cServerCredentials;
 
 /* Initializes the ruby ServerCredentials class. */
 void Init_grpc_server_credentials();