diff --git a/clang/lib/Basic/Version.cpp b/clang/lib/Basic/Version.cpp
--- a/clang/lib/Basic/Version.cpp
+++ b/clang/lib/Basic/Version.cpp
@@ -97,8 +97,12 @@
 #ifdef CLANG_VENDOR
   OS << CLANG_VENDOR;
 #endif
-  OS << ToolName << " version " CLANG_VERSION_STRING " "
-     << getClangFullRepositoryVersion();
+  OS << ToolName << " version " CLANG_VERSION_STRING;
+
+  std::string repo = getClangFullRepositoryVersion();
+  if (!repo.empty()) {
+    OS << " " << repo;
+  }
 
   return OS.str();
 }
@@ -111,7 +115,13 @@
 #ifdef CLANG_VENDOR
   OS << CLANG_VENDOR;
 #endif
-  OS << "Clang " CLANG_VERSION_STRING " " << getClangFullRepositoryVersion();
+  OS << "Clang " CLANG_VERSION_STRING;
+
+  std::string repo = getClangFullRepositoryVersion();
+  if (!repo.empty()) {
+    OS << " " << repo;
+  }
+
   return OS.str();
 }