diff --git a/desmume/src/frontend/modules/ImageOut.cpp b/desmume/src/frontend/modules/ImageOut.cpp
index d0b5e6511..c06e9caab 100644
--- a/desmume/src/frontend/modules/ImageOut.cpp
+++ b/desmume/src/frontend/modules/ImageOut.cpp
@@ -15,6 +15,7 @@
 	along with the this software.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <stdlib.h>
 #include <stdio.h>
 #include <zlib.h>
 #include "types.h"