diff --git a/exec.c b/exec.c
index 5f2a87c239..a1553ba10b 100644
--- a/exec.c
+++ b/exec.c
@@ -21,6 +21,7 @@
 #ifdef _WIN32
 #include <windows.h>
 #else
+#include <sys/types.h>
 #include <sys/mman.h>
 #endif
 #include <stdlib.h>