diff --git a/src/filepath.c b/src/filepath.c
index 4ddeeaf..8da6e17 100644
--- a/src/filepath.c
+++ b/src/filepath.c
@@ -79,7 +79,7 @@
     vim_free(wfname);
     vim_free(newbuf);
 
-    *fnamelen = l == 0 ? l : STRLEN(*bufp);
+    *fnamelen = l == 0 ? l : (int)STRLEN(*bufp);
     return OK;
 }