diff --git a/src/ops.c b/src/ops.c
index ca327b9..37c6aab 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -4352,7 +4352,7 @@
 
 		char_u *new_curr = skip_comment(curr, TRUE, insert_space,
 							   &prev_was_comment);
-		comments[t] = new_curr - curr;
+		comments[t] = (int)(new_curr - curr);
 		curr = new_curr;
 	    }
 	    else