diff --git a/include/compat/unistd.h b/include/compat/unistd.h
index 4c4df10..5e6ab1d 100644
--- a/include/compat/unistd.h
+++ b/include/compat/unistd.h
@@ -38,6 +38,7 @@ ssize_t pwrite(int d, const void *buf, size_t nbytes, off_t offset);
 #define access _access
 
 #ifdef _MSC_VER
+#include <windows.h>
 static inline unsigned int sleep(unsigned int seconds)
 {
        Sleep(seconds * 1000);