diff --git a/contrib/mobile/drawString.h b/contrib/mobile/drawString.h
index 0cf8fb70e43c27590ed41c60ee0ee761e6e7f5b9..b1afad21fabccb38fad6b1168f82e3f8dd778e2c 100644
--- a/contrib/mobile/drawString.h
+++ b/contrib/mobile/drawString.h
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <string>
 
 #if defined(BUILD_ANDROID)