diff --git a/src/ar65/library.c b/src/ar65/library.c
index 991cfe110..342bc25d3 100644
--- a/src/ar65/library.c
+++ b/src/ar65/library.c
@@ -36,8 +36,12 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
+#if defined(_WIN32)
+#include <process.h>
+#else
 #include <sys/types.h>
 #include <unistd.h>
+#endif
 
 /* common */
 #include "cmdline.h"