diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1111,7 +1111,7 @@
           },
           /*EnclosingFunctionNames=*/
           {},
-          /*CanonicalDelimiter=*/"",
+          /*CanonicalDelimiter=*/"pb",
           /*BasedOnStyle=*/"google",
       },
       {