diff --git a/src/graphviz_parser.y b/src/graphviz_parser.y
index 94c59c17..e9b887ab 100644
--- a/src/graphviz_parser.y
+++ b/src/graphviz_parser.y
@@ -218,7 +218,7 @@
       char buf[256];
       sprintf(buf, "default%i\0", i);
       ++i;
-      return  string(buf);
+      return std::string(buf);
 #else
       std::stringstream out;
       out << "default" << i;