diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -116,7 +116,11 @@
     while (CurrentToken) {
       if (CurrentToken->is(tok::greater)) {
         // Try to do a better job at looking for ">>" within the condition of
-        // a statement.
+        // a statement. Conservatively insert spaces between consecutive ">"
+        // tokens to prevent splitting right bitshift operators and potentially
+        // altering program semantics. This check is overly conservative and
+        // will prevent spaces from being inserted in select nested template
+        // parameter cases, but should not alter program semantics.
         if (CurrentToken->Next && CurrentToken->Next->is(tok::greater) &&
             Left->ParentBracket != tok::less &&
             (isKeywordWithCondition(*Line.First) ||