diff --git a/src/google/protobuf/compiler/command_line_interface_unittest.cc b/src/google/protobuf/compiler/command_line_interface_unittest.cc
index a2cbbdc614..e284c7915b 100644
--- a/src/google/protobuf/compiler/command_line_interface_unittest.cc
+++ b/src/google/protobuf/compiler/command_line_interface_unittest.cc
@@ -288,6 +288,7 @@ void CommandLineInterfaceTest::Run(const string& command) {
 
   if (!disallow_plugins_) {
     cli_.AllowPlugins("prefix-");
+#ifndef GOOGLE_THIRD_PARTY_PROTOBUF
     const char* possible_paths[] = {
       // When building with shared libraries, libtool hides the real executable
       // in .libs and puts a fake wrapper in the current directory.
@@ -316,6 +317,11 @@ void CommandLineInterfaceTest::Run(const string& command) {
     }
 
     if (plugin_path.empty()) {
+#else
+    string plugin_path = "third_party/protobuf/test_plugin";
+
+    if (access(plugin_path.c_str(), F_OK) != 0) {
+#endif  // GOOGLE_THIRD_PARTY_PROTOBUF
       GOOGLE_LOG(ERROR)
           << "Plugin executable not found.  Plugin tests are likely to fail.";
     } else {
diff --git a/src/google/protobuf/testing/googletest.cc b/src/google/protobuf/testing/googletest.cc
index d72fa5c00d..5f6a199af1 100644
--- a/src/google/protobuf/testing/googletest.cc
+++ b/src/google/protobuf/testing/googletest.cc
@@ -65,6 +65,7 @@ namespace protobuf {
 #endif
 
 string TestSourceDir() {
+#ifndef GOOGLE_THIRD_PARTY_PROTOBUF
 #ifdef _MSC_VER
   // Look for the "src" directory.
   string prefix = ".";
@@ -88,6 +89,9 @@ string TestSourceDir() {
     return result;
   }
 #endif
+#else
+  return "third_party/protobuf/src";
+#endif  // GOOGLE_THIRD_PARTY_PROTOBUF
 }
 
 namespace {