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
@@ -2481,9 +2481,13 @@
   //   {
   //     return i + 1;
   //   }
-  if (Next->Next && Next->Next->is(tok::identifier) &&
-      Line.Last->isNot(tok::semi))
-    return true;
+  if (Next->Next && Next->Next->is(tok::identifier)) {
+    const FormatToken *Last = Line.Last;
+    if (Last && Last->is(tok::comment))
+      Last = Last->getPreviousNonComment();
+    if (Last && Last->isNot(tok::semi))
+      return true;
+  }
   for (const FormatToken *Tok = Next->Next; Tok && Tok != Next->MatchingParen;
        Tok = Tok->Next) {
     if (Tok->is(TT_TypeDeclarationParen))
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -8252,6 +8252,9 @@
   verifyFormat("Tttttttttttttttttttttttt ppppppppppppppp\n"
                "    ABSL_GUARDED_BY(mutex) = {};",
                getGoogleStyleWithColumns(40));
+  verifyFormat("Tttttttttttttttttttttttt ppppppppppppppp\n"
+               "    ABSL_GUARDED_BY(mutex);  // comment",
+               getGoogleStyleWithColumns(40));
 
   Style = getGNUStyle();