diff --git a/sequencer.c b/sequencer.c
index 31e4d3fdec..e29a01944b 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3636,13 +3636,24 @@ static int error_with_patch(struct repository *r,
 			    struct replay_opts *opts,
 			    int exit_code, int to_amend)
 {
-	if (commit) {
-		if (make_patch(r, commit, opts))
+	struct replay_ctx *ctx = opts->ctx;
+
+	/*
+	 * Write the commit message to be used by "git rebase
+	 * --continue". If a "fixup" or "squash" command has conflicts
+	 * then we will have already written rebase_path_message() in
+	 * error_failed_squash(). If an "edit" command was
+	 * fast-forwarded then we don't have a message in ctx->message
+	 * and rely on make_patch() to write rebase_path_message()
+	 * instead.
+	 */
+	if (ctx->have_message && !file_exists(rebase_path_message()) &&
+	    write_message(ctx->message.buf, ctx->message.len,
+			  rebase_path_message(), 0))
+		return error(_("could not write commit message file"));
+
+	if (commit && make_patch(r, commit, opts))
 			return -1;
-	} else if (copy_file(rebase_path_message(),
-			     git_path_merge_msg(r), 0666))
-		return error(_("unable to copy '%s' to '%s'"),
-			     git_path_merge_msg(r), rebase_path_message());
 
 	if (to_amend) {
 		if (intend_to_amend())
diff --git a/t/t3428-rebase-signoff.sh b/t/t3428-rebase-signoff.sh
index 1bebd1ce74..6f57aed9fa 100755
--- a/t/t3428-rebase-signoff.sh
+++ b/t/t3428-rebase-signoff.sh
@@ -5,12 +5,17 @@ test_description='git rebase --signoff
 This test runs git rebase --signoff and make sure that it works.
 '
 
-TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-rebase.sh
 
 test_expect_success 'setup' '
 	git commit --allow-empty -m "Initial empty commit" &&
 	test_commit first file a &&
+	test_commit second file &&
+	git checkout -b conflict-branch first &&
+	test_commit file-2 file-2 &&
+	test_commit conflict file &&
+	test_commit third file &&
 
 	ident="$GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>" &&
 
@@ -28,6 +33,22 @@ test_expect_success 'setup' '
 	Signed-off-by: $ident
 	EOF
 
+	# Expected commit message after conflict resolution for rebase --signoff
+	cat >expected-signed-conflict <<-EOF &&
+	third
+
+	Signed-off-by: $ident
+
+	conflict
+
+	Signed-off-by: $ident
+
+	file-2
+
+	Signed-off-by: $ident
+
+	EOF
+
 	# Expected commit message after rebase without --signoff (or with --no-signoff)
 	cat >expected-unsigned <<-EOF &&
 	first
@@ -39,8 +60,12 @@ test_expect_success 'setup' '
 # We configure an alias to do the rebase --signoff so that
 # on the next subtest we can show that --no-signoff overrides the alias
 test_expect_success 'rebase --apply --signoff adds a sign-off line' '
-	git rbs --apply HEAD^ &&
-	test_commit_message HEAD expected-signed
+	test_must_fail git rbs --apply second third &&
+	git checkout --theirs file &&
+	git add file &&
+	git rebase --continue &&
+	git log --format=%B -n3 >actual &&
+	test_cmp expected-signed-conflict actual
 '
 
 test_expect_success 'rebase --no-signoff does not add a sign-off line' '
@@ -51,28 +76,65 @@ test_expect_success 'rebase --no-signoff does not add a sign-off line' '
 
 test_expect_success 'rebase --exec --signoff adds a sign-off line' '
 	test_when_finished "rm exec" &&
-	git commit --amend -m "first" &&
-	git rebase --exec "touch exec" --signoff HEAD^ &&
+	git rebase --exec "touch exec" --signoff first^ first &&
 	test_path_is_file exec &&
 	test_commit_message HEAD expected-signed
 '
 
 test_expect_success 'rebase --root --signoff adds a sign-off line' '
-	git commit --amend -m "first" &&
+	git checkout first &&
 	git rebase --root --keep-empty --signoff &&
 	test_commit_message HEAD^ expected-initial-signed &&
 	test_commit_message HEAD expected-signed
 '
 
-test_expect_success 'rebase -i --signoff fails' '
-	git commit --amend -m "first" &&
-	git rebase -i --signoff HEAD^ &&
-	test_commit_message HEAD expected-signed
+test_expect_success 'rebase -m --signoff adds a sign-off line' '
+	test_must_fail git rebase -m --signoff second third &&
+	git checkout --theirs file &&
+	git add file &&
+	GIT_EDITOR="sed -n /Conflicts:/,/^\\\$/p >actual" \
+		git rebase --continue &&
+	cat >expect <<-\EOF &&
+	# Conflicts:
+	#	file
+
+	EOF
+	test_cmp expect actual &&
+	git log --format=%B -n3 >actual &&
+	test_cmp expected-signed-conflict actual
 '
 
-test_expect_success 'rebase -m --signoff fails' '
-	git commit --amend -m "first" &&
-	git rebase -m --signoff HEAD^ &&
-	test_commit_message HEAD expected-signed
+test_expect_success 'rebase -i --signoff adds a sign-off line when editing commit' '
+	(
+		set_fake_editor &&
+		FAKE_LINES="edit 1 edit 3 edit 2" \
+			git rebase -i --signoff first third
+	) &&
+	echo a >a &&
+	git add a &&
+	test_must_fail git rebase --continue &&
+	git checkout --ours file &&
+	echo b >a &&
+	git add a file &&
+	git rebase --continue &&
+	echo c >a &&
+	git add a &&
+	git log --format=%B -n3 >actual &&
+	cat >expect <<-EOF &&
+	conflict
+
+	Signed-off-by: $ident
+
+	third
+
+	Signed-off-by: $ident
+
+	file-2
+
+	Signed-off-by: $ident
+
+	EOF
+	test_cmp expect actual
 '
+
 test_done
diff --git a/t/t3434-rebase-i18n.sh b/t/t3434-rebase-i18n.sh
index e6fef696bb..a4e482d2cd 100755
--- a/t/t3434-rebase-i18n.sh
+++ b/t/t3434-rebase-i18n.sh
@@ -71,7 +71,7 @@ test_rebase_continue_update_encode () {
 		git config i18n.commitencoding $new &&
 		test_must_fail git rebase -m main &&
 		test -f .git/rebase-merge/message &&
-		git stripspace <.git/rebase-merge/message >two.t &&
+		git stripspace -s <.git/rebase-merge/message >two.t &&
 		git add two.t &&
 		git rebase --continue &&
 		compare_msg $msgfile $old $new &&