diff --git a/test/WriteFile.cxx b/test/WriteFile.cxx
index 57e2c990f..a281d379d 100644
--- a/test/WriteFile.cxx
+++ b/test/WriteFile.cxx
@@ -24,7 +24,9 @@
 
 #include <unistd.h>
 #include <errno.h>
+
 #include <string.h>
+#include <stdlib.h>
 
 static bool
 Copy(OutputStream &dest, int src)