diff --git a/convert/source-fs.h b/convert/source-fs.h
index 23f33567..4e5babef 100644
--- a/convert/source-fs.h
+++ b/convert/source-fs.h
@@ -19,6 +19,7 @@
 
 #include "kerncompat.h"
 #include <linux/kdev_t.h>
+#include <sys/types.h>
 #include <pthread.h>
 
 #define CONV_IMAGE_SUBVOL_OBJECTID BTRFS_FIRST_FREE_OBJECTID