diff --git a/sequencer.c b/sequencer.c
index 8909a46770..a59e0c84af 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1757,11 +1757,10 @@ static int update_squash_messages(struct repository *r,
 			return error(_("could not read HEAD's commit message"));
 
 		find_commit_subject(head_message, &body);
-		if (write_message(body, strlen(body),
-				  rebase_path_fixup_msg(), 0)) {
+		if (command == TODO_FIXUP && write_message(body, strlen(body),
+							rebase_path_fixup_msg(), 0) < 0) {
 			unuse_commit_buffer(head_commit, head_message);
-			return error(_("cannot write '%s'"),
-				     rebase_path_fixup_msg());
+			return error(_("cannot write '%s'"), rebase_path_fixup_msg());
 		}
 
 		strbuf_addf(&buf, "%c ", comment_line_char);