diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index f636bb746d45..0a7d18af98bd 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -3469,11 +3469,15 @@ cp_parser_diagnose_invalid_type_name (cp_parser *parser, tree id,
       else if (TREE_CODE (id) == IDENTIFIER_NODE
 	       && (id_equal (id, "module") || id_equal (id, "import")))
 	{
-	  if (!modules_p ())
-	    inform (location, "%qE only available with %<-fmodules-ts%>", id);
-	  else
-	    inform (location, "%qE was not recognized as a module control-line",
+	  if (modules_p ())
+	    inform (location, "%qE is not recognized as a module control-line",
 		    id);
+	  else if (cxx_dialect < cxx20)
+	    inform (location, "C++20 %qE only available with %<-fmodules-ts%>",
+		    id);
+	  else
+	    inform (location, "C++20 %qE only available with %<-fmodules-ts%>"
+		    ", which is not yet enabled with %<-std=c++20%>", id);
 	}
       else if (cxx_dialect < cxx11
 	       && TREE_CODE (id) == IDENTIFIER_NODE