diff --git a/src/os/macosx/osx_stdafx.h b/src/os/macosx/osx_stdafx.h
index 70dc8030cc..1481d01130 100644
--- a/src/os/macosx/osx_stdafx.h
+++ b/src/os/macosx/osx_stdafx.h
@@ -85,6 +85,7 @@
 
 #include <CoreServices/CoreServices.h>
 #include <ApplicationServices/ApplicationServices.h>
+#include <string>
 
 #undef Rect
 #undef Point