diff --git a/src/nvim/window.c b/src/nvim/window.c
index e9a66ad907..0be586c606 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -482,7 +482,7 @@ wingotofile:
 }
 
 static void cmd_with_count(char *cmd, char_u *bufp, size_t bufsize,
-                           long Prenum)
+                           int64_t Prenum)
 {
   size_t len = xstrlcpy((char *)bufp, cmd, bufsize);