diff --git a/lib/zip_source_win32a.c b/lib/zip_source_win32a.c
index 7466279..064d9b2 100644
--- a/lib/zip_source_win32a.c
+++ b/lib/zip_source_win32a.c
@@ -33,6 +33,7 @@
 
 
 #include <stdio.h>
+#include <stdlib.h>
 
 #include "zipint.h"
 #include "zipwin32.h"
diff --git a/lib/zip_source_win32w.c b/lib/zip_source_win32w.c
index 2ae244f..dcf310c 100644
--- a/lib/zip_source_win32w.c
+++ b/lib/zip_source_win32w.c
@@ -33,6 +33,7 @@
 
 
 #include <stdio.h>
+#include <stdlib.h>
 
 #include "zipint.h"
 #include "zipwin32.h"