diff --git a/src/ui/map3D/GCManipulator.cc b/src/ui/map3D/GCManipulator.cc
index cdabc966533ea9f53448713144bcbd9b584f5e6b..98385365719468fa1f3b41be0a79d968a1d5524b 100644
--- a/src/ui/map3D/GCManipulator.cc
+++ b/src/ui/map3D/GCManipulator.cc
@@ -254,7 +254,11 @@ GCManipulator::calcMovement()
     if (buttonMask == GUIEventAdapter::LEFT_MOUSE_BUTTON)
     {
         // rotate camera
+#ifdef __APPLE__
+        osg::Vec3d axis;
+#else
         osg::Vec3 axis;
+#endif
         float angle;
 
         float px0 = _ga_t0->getXnormalized();