diff --git a/test/core/end2end/cq_verifier.c b/test/core/end2end/cq_verifier.c
index 5eea5d4..0fafb0c 100644
--- a/test/core/end2end/cq_verifier.c
+++ b/test/core/end2end/cq_verifier.c
@@ -77,7 +77,7 @@
 };
 
 cq_verifier *cq_verifier_create(grpc_completion_queue *cq) {
-  cq_verifier *v = gpr_malloc(sizeof(cq_verifier));
+  cq_verifier *v = (cq_verifier *)gpr_malloc(sizeof(cq_verifier));
   v->cq = cq;
   v->first_expectation = NULL;
   return v;
@@ -314,7 +314,7 @@
 
 static void add(cq_verifier *v, const char *file, int line,
                 grpc_completion_type type, void *tag, bool success) {
-  expectation *e = gpr_malloc(sizeof(expectation));
+  expectation *e = (expectation *)gpr_malloc(sizeof(expectation));
   e->type = type;
   e->file = file;
   e->line = line;
diff --git a/test/core/end2end/fake_resolver.c b/test/core/end2end/fake_resolver.c
index df902a2..736b224 100644
--- a/test/core/end2end/fake_resolver.c
+++ b/test/core/end2end/fake_resolver.c
@@ -136,7 +136,7 @@
 grpc_fake_resolver_response_generator*
 grpc_fake_resolver_response_generator_create() {
   grpc_fake_resolver_response_generator* generator =
-      gpr_zalloc(sizeof(*generator));
+      (grpc_fake_resolver_response_generator*)gpr_zalloc(sizeof(*generator));
   gpr_ref_init(&generator->refcount, 1);
   return generator;
 }
@@ -157,7 +157,8 @@
 
 static void set_response_cb(grpc_exec_ctx* exec_ctx, void* arg,
                             grpc_error* error) {
-  grpc_fake_resolver_response_generator* generator = arg;
+  grpc_fake_resolver_response_generator* generator =
+      (grpc_fake_resolver_response_generator*)arg;
   fake_resolver* r = generator->resolver;
   if (r->next_results != NULL) {
     grpc_channel_args_destroy(exec_ctx, r->next_results);
@@ -180,11 +181,13 @@
 }
 
 static void* response_generator_arg_copy(void* p) {
-  return grpc_fake_resolver_response_generator_ref(p);
+  return grpc_fake_resolver_response_generator_ref(
+      (grpc_fake_resolver_response_generator*)p);
 }
 
 static void response_generator_arg_destroy(grpc_exec_ctx* exec_ctx, void* p) {
-  grpc_fake_resolver_response_generator_unref(p);
+  grpc_fake_resolver_response_generator_unref(
+      (grpc_fake_resolver_response_generator*)p);
 }
 
 static int response_generator_cmp(void* a, void* b) { return GPR_ICMP(a, b); }
@@ -208,7 +211,7 @@
   const grpc_arg* arg =
       grpc_channel_args_find(args, GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR);
   if (arg == NULL || arg->type != GRPC_ARG_POINTER) return NULL;
-  return arg->value.pointer.p;
+  return (grpc_fake_resolver_response_generator*)arg->value.pointer.p;
 }
 
 //
@@ -222,7 +225,7 @@
 static grpc_resolver* fake_resolver_create(grpc_exec_ctx* exec_ctx,
                                            grpc_resolver_factory* factory,
                                            grpc_resolver_args* args) {
-  fake_resolver* r = gpr_zalloc(sizeof(*r));
+  fake_resolver* r = (fake_resolver*)gpr_zalloc(sizeof(*r));
   r->channel_args = grpc_channel_args_copy(args->args);
   grpc_resolver_init(&r->base, &fake_resolver_vtable, args->combiner);
   grpc_fake_resolver_response_generator* response_generator =
diff --git a/test/core/end2end/fixtures/http_proxy_fixture.c b/test/core/end2end/fixtures/http_proxy_fixture.c
index f0d0948..5df43b9 100644
--- a/test/core/end2end/fixtures/http_proxy_fixture.c
+++ b/test/core/end2end/fixtures/http_proxy_fixture.c
@@ -156,7 +156,7 @@
 // Callback for writing proxy data to the client.
 static void on_client_write_done(grpc_exec_ctx* exec_ctx, void* arg,
                                  grpc_error* error) {
-  proxy_connection* conn = arg;
+  proxy_connection* conn = (proxy_connection*)arg;
   if (error != GRPC_ERROR_NONE) {
     proxy_connection_failed(exec_ctx, conn, true /* is_client */,
                             "HTTP proxy client write", error);
@@ -181,7 +181,7 @@
 // Callback for writing proxy data to the backend server.
 static void on_server_write_done(grpc_exec_ctx* exec_ctx, void* arg,
                                  grpc_error* error) {
-  proxy_connection* conn = arg;
+  proxy_connection* conn = (proxy_connection*)arg;
   if (error != GRPC_ERROR_NONE) {
     proxy_connection_failed(exec_ctx, conn, false /* is_client */,
                             "HTTP proxy server write", error);
@@ -207,7 +207,7 @@
 // the backend server.
 static void on_client_read_done(grpc_exec_ctx* exec_ctx, void* arg,
                                 grpc_error* error) {
-  proxy_connection* conn = arg;
+  proxy_connection* conn = (proxy_connection*)arg;
   if (error != GRPC_ERROR_NONE) {
     proxy_connection_failed(exec_ctx, conn, true /* is_client */,
                             "HTTP proxy client read", error);
@@ -239,7 +239,7 @@
 // proxied to the client.
 static void on_server_read_done(grpc_exec_ctx* exec_ctx, void* arg,
                                 grpc_error* error) {
-  proxy_connection* conn = arg;
+  proxy_connection* conn = (proxy_connection*)arg;
   if (error != GRPC_ERROR_NONE) {
     proxy_connection_failed(exec_ctx, conn, false /* is_client */,
                             "HTTP proxy server read", error);
@@ -270,7 +270,7 @@
 // Callback to write the HTTP response for the CONNECT request.
 static void on_write_response_done(grpc_exec_ctx* exec_ctx, void* arg,
                                    grpc_error* error) {
-  proxy_connection* conn = arg;
+  proxy_connection* conn = (proxy_connection*)arg;
   if (error != GRPC_ERROR_NONE) {
     proxy_connection_failed(exec_ctx, conn, true /* is_client */,
                             "HTTP proxy write response", error);
@@ -294,7 +294,7 @@
 // CONNECT request.
 static void on_server_connect_done(grpc_exec_ctx* exec_ctx, void* arg,
                                    grpc_error* error) {
-  proxy_connection* conn = arg;
+  proxy_connection* conn = (proxy_connection*)arg;
   if (error != GRPC_ERROR_NONE) {
     // TODO(roth): Technically, in this case, we should handle the error
     // by returning an HTTP response to the client indicating that the
@@ -324,7 +324,7 @@
 // which will cause the client connection to be dropped.
 static void on_read_request_done(grpc_exec_ctx* exec_ctx, void* arg,
                                  grpc_error* error) {
-  proxy_connection* conn = arg;
+  proxy_connection* conn = (proxy_connection*)arg;
   gpr_log(GPR_DEBUG, "on_read_request_done: %p %s", conn,
           grpc_error_string(error));
   if (error != GRPC_ERROR_NONE) {
@@ -389,9 +389,9 @@
                       grpc_endpoint* endpoint, grpc_pollset* accepting_pollset,
                       grpc_tcp_server_acceptor* acceptor) {
   gpr_free(acceptor);
-  grpc_end2end_http_proxy* proxy = arg;
+  grpc_end2end_http_proxy* proxy = (grpc_end2end_http_proxy*)arg;
   // Instantiate proxy_connection.
-  proxy_connection* conn = gpr_zalloc(sizeof(*conn));
+  proxy_connection* conn = (proxy_connection*)gpr_zalloc(sizeof(*conn));
   gpr_ref(&proxy->users);
   conn->client_endpoint = endpoint;
   conn->proxy = proxy;
@@ -430,7 +430,7 @@
 //
 
 static void thread_main(void* arg) {
-  grpc_end2end_http_proxy* proxy = arg;
+  grpc_end2end_http_proxy* proxy = (grpc_end2end_http_proxy*)arg;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   do {
     gpr_ref(&proxy->users);
@@ -450,7 +450,8 @@
 
 grpc_end2end_http_proxy* grpc_end2end_http_proxy_create(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_end2end_http_proxy* proxy = gpr_malloc(sizeof(*proxy));
+  grpc_end2end_http_proxy* proxy =
+      (grpc_end2end_http_proxy*)gpr_malloc(sizeof(*proxy));
   memset(proxy, 0, sizeof(*proxy));
   gpr_ref_init(&proxy->users, 1);
   // Construct proxy address.
@@ -473,7 +474,7 @@
   GPR_ASSERT(error == GRPC_ERROR_NONE);
   GPR_ASSERT(port == proxy_port);
   // Start server.
-  proxy->pollset = gpr_zalloc(grpc_pollset_size());
+  proxy->pollset = (grpc_pollset*)gpr_zalloc(grpc_pollset_size());
   grpc_pollset_init(proxy->pollset, &proxy->mu);
   grpc_tcp_server_start(&exec_ctx, proxy->server, &proxy->pollset, 1, on_accept,
                         proxy);
@@ -487,7 +488,7 @@
 
 static void destroy_pollset(grpc_exec_ctx* exec_ctx, void* arg,
                             grpc_error* error) {
-  grpc_pollset* pollset = arg;
+  grpc_pollset* pollset = (grpc_pollset*)arg;
   grpc_pollset_destroy(pollset);
   gpr_free(pollset);
 }
diff --git a/test/core/security/oauth2_utils.c b/test/core/security/oauth2_utils.c
index f0550db..8386257 100644
--- a/test/core/security/oauth2_utils.c
+++ b/test/core/security/oauth2_utils.c
@@ -55,7 +55,7 @@
                                grpc_credentials_md *md_elems, size_t num_md,
                                grpc_credentials_status status,
                                const char *error_details) {
-  oauth2_request *request = user_data;
+  oauth2_request *request = (oauth2_request *)user_data;
   char *token = NULL;
   grpc_slice token_slice;
   if (status == GRPC_CREDENTIALS_ERROR) {
@@ -63,7 +63,7 @@
   } else {
     GPR_ASSERT(num_md == 1);
     token_slice = md_elems[0].value;
-    token = gpr_malloc(GRPC_SLICE_LENGTH(token_slice) + 1);
+    token = (char *)gpr_malloc(GRPC_SLICE_LENGTH(token_slice) + 1);
     memcpy(token, GRPC_SLICE_START_PTR(token_slice),
            GRPC_SLICE_LENGTH(token_slice));
     token[GRPC_SLICE_LENGTH(token_slice)] = '\0';
@@ -87,7 +87,7 @@
   grpc_closure do_nothing_closure;
   grpc_auth_metadata_context null_ctx = {"", "", NULL, NULL};
 
-  grpc_pollset *pollset = gpr_zalloc(grpc_pollset_size());
+  grpc_pollset *pollset = (grpc_pollset *)gpr_zalloc(grpc_pollset_size());
   grpc_pollset_init(pollset, &request.mu);
   request.pops = grpc_polling_entity_create_from_pollset(pollset);
   request.is_done = 0;