diff --git a/src/core/os.c b/src/core/os.c
index a0a840cc..b7b562c9 100644
--- a/src/core/os.c
+++ b/src/core/os.c
@@ -41,6 +41,7 @@
 #include <direct.h>
 #include <sys/utime.h>
 #include <io.h>
+#include <process.h>
 #else
 #include <spawn.h>
 #include <utime.h>