diff --git a/src/Base/Builder3D.cpp b/src/Base/Builder3D.cpp
index 7aa4ecacd9..b08df85ec6 100644
--- a/src/Base/Builder3D.cpp
+++ b/src/Base/Builder3D.cpp
@@ -172,7 +172,10 @@ void Builder3D::addText(const Base::Vector3f &vec,const char * text, float color
 
 void Builder3D::clear ()
 {
+  // under gcc stringstream::str() returns a copy not a reference
+#if defined(_MSC_VER)
   result.str().clear();
+#endif
   result.clear();
 }