Index: clang-tidy/readability/IdentifierNamingCheck.cpp
===================================================================
--- clang-tidy/readability/IdentifierNamingCheck.cpp
+++ clang-tidy/readability/IdentifierNamingCheck.cpp
@@ -567,10 +567,11 @@
     SourceRange DeclRange =
         DeclarationNameInfo(Decl.getDeclName(), Decl.getLocation())
             .getSourceRange();
-    auto Diag = diag(Decl.getLocStart(), "invalid case style for %0 '%1'")
-                << Failure.KindName << Decl.getName();
 
     if (Failure.ShouldFix) {
+      auto Diag = diag(Decl.getLocStart(), "invalid case style for %0 '%1'")
+                  << Failure.KindName << Decl.getName();
+
       Diag << FixItHint::CreateReplacement(
           CharSourceRange::getTokenRange(DeclRange), Failure.Fixup);