diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 846c90c7ae4..a81218fe222 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2062,7 +2062,16 @@ funcname_signature_string(const char *funcname, int nargs,
 
 	initStringInfo(&argbuf);
 
-	if (sql_dialect == SQL_DIALECT_TSQL && remove_db_name_in_schema_hook) {
+	/* Check if there is schema in funcname */
+	char * ptr = funcname;
+	while (ptr) {
+		if (*ptr == '.') {
+            break;
+        }
+        ptr++;
+	}
+
+	if (sql_dialect == SQL_DIALECT_TSQL && remove_db_name_in_schema_hook && ptr) {
 		funcname = (*remove_db_name_in_schema_hook)(funcname);
 	}