Add missing dependency
diff --git a/BUILD b/BUILD
index 3122dc0..24d27ab 100644
--- a/BUILD
+++ b/BUILD
@@ -1219,6 +1219,9 @@
     public_hdrs = [
         "include/grpc++/impl/codegen/config_protobuf.h",
     ],
+    external_deps = [
+        "protobuf",
+    ],
 )
 
 grpc_cc_library(