diff --git a/CHANGELOG.md b/CHANGELOG.md
index edacc3cb46..a703a6dfe2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * File path arguments now support [file pattern
   syntax](docs/filesets.md#file-patterns).
 
+* `jj prev` and `jj next` now work when the working copy revision is a merge.
+
 * Operation objects in templates now have a `snapshot() -> Boolean` method that
   evaluates to true if the operation was a snapshot created by a non-mutating
   command (e.g. `jj log`).
diff --git a/cli/src/commands/next.rs b/cli/src/commands/next.rs
index 19ad069ca6..e8687244a3 100644
--- a/cli/src/commands/next.rs
+++ b/cli/src/commands/next.rs
@@ -105,7 +105,6 @@ pub(crate) fn cmd_next(
     args: &NextArgs,
 ) -> Result<(), CommandError> {
     let mut workspace_command = command.workspace_helper(ui)?;
-    let offset = args.offset;
     let current_wc_id = workspace_command
         .get_wc_commit_id()
         .ok_or_else(|| user_error("This command requires a working copy"))?;
@@ -115,24 +114,20 @@ pub(crate) fn cmd_next(
             .view()
             .heads()
             .contains(current_wc_id);
-    let current_wc = workspace_command.repo().store().get_commit(current_wc_id)?;
-    // If we're editing, start at the working-copy commit.
-    // Otherwise start from our direct parent.
-    let start_id = if edit {
-        current_wc_id
+    let wc_revset = RevsetExpression::commit(current_wc_id.clone());
+    // If we're editing, start at the working-copy commit. Otherwise, start from
+    // its direct parent(s).
+    let target_revset = if edit {
+        wc_revset.descendants_at(args.offset)
     } else {
-        match current_wc.parent_ids() {
-            [parent_id] => parent_id,
-            _ => return Err(user_error("Cannot run `jj next` on a merge commit")),
-        }
-    };
-    let descendant_expression = RevsetExpression::commit(start_id.clone()).descendants_at(offset);
-    let target_expression = if edit {
-        descendant_expression
-    } else {
-        descendant_expression.minus(&RevsetExpression::commit(current_wc_id.clone()).descendants())
+        wc_revset
+            .parents()
+            .descendants_at(args.offset)
+            // In previous versions we subtracted `wc_revset.descendants()`. That's
+            // unnecessary now that --edit is implied if `@` has descendants.
+            .minus(&wc_revset)
     };
-    let targets: Vec<Commit> = target_expression
+    let targets: Vec<Commit> = target_revset
         .evaluate_programmatic(workspace_command.repo().as_ref())?
         .iter()
         .commits(workspace_command.repo().store())
@@ -142,13 +137,14 @@ pub(crate) fn cmd_next(
         [] => {
             // We found no descendant.
             return Err(user_error(format!(
-                "No descendant found {offset} commit{} forward",
-                if offset > 1 { "s" } else { "" }
+                "No descendant found {} commit{} forward",
+                args.offset,
+                if args.offset > 1 { "s" } else { "" }
             )));
         }
         commits => choose_commit(ui, &workspace_command, "next", commits)?,
     };
-    let current_short = short_commit_hash(current_wc.id());
+    let current_short = short_commit_hash(current_wc_id);
     let target_short = short_commit_hash(target.id());
     // We're editing, just move to the target commit.
     if edit {
diff --git a/cli/src/commands/prev.rs b/cli/src/commands/prev.rs
index 11c84efe98..703e947d8a 100644
--- a/cli/src/commands/prev.rs
+++ b/cli/src/commands/prev.rs
@@ -50,7 +50,6 @@ use crate::ui::Ui;
 /// ```
 /// If the working copy revision already has visible children, then `--edit` is
 /// implied.
-// TODO(#2126): Handle multiple parents, e.g merges.
 #[derive(clap::Args, Clone, Debug)]
 #[command(verbatim_doc_comment)]
 pub(crate) struct PrevArgs {
@@ -68,7 +67,6 @@ pub(crate) fn cmd_prev(
     args: &PrevArgs,
 ) -> Result<(), CommandError> {
     let mut workspace_command = command.workspace_helper(ui)?;
-    let offset = args.offset;
     let current_wc_id = workspace_command
         .get_wc_commit_id()
         .ok_or_else(|| user_error("This command requires a working copy"))?;
@@ -78,25 +76,14 @@ pub(crate) fn cmd_prev(
             .view()
             .heads()
             .contains(current_wc_id);
-    let current_wc = workspace_command.repo().store().get_commit(current_wc_id)?;
-    let start_id = if edit {
-        current_wc_id
-    } else {
-        match current_wc.parent_ids() {
-            [parent_id] => parent_id,
-            _ => return Err(user_error("Cannot run `jj prev` on a merge commit")),
-        }
-    };
-    let ancestor_expression = RevsetExpression::commit(start_id.clone()).ancestors_at(offset);
+    // If we're editing, start at the working-copy commit. Otherwise, start from
+    // its direct parent(s).
     let target_revset = if edit {
-        ancestor_expression
+        RevsetExpression::commit(current_wc_id.clone()).ancestors_at(args.offset)
     } else {
-        // Jujutsu will always create a new commit for prev, even where Mercurial cannot
-        // and fails. The decision and all discussion around it are available
-        // here: https://github.com/martinvonz/jj/pull/1200#discussion_r1298623933
-        //
-        // If users ever request erroring out, add `.ancestors()` to the revset below.
-        ancestor_expression.minus(&RevsetExpression::commit(current_wc_id.clone()))
+        RevsetExpression::commit(current_wc_id.clone())
+            .parents()
+            .ancestors_at(args.offset)
     };
     let targets: Vec<_> = target_revset
         .evaluate_programmatic(workspace_command.repo().as_ref())?
@@ -107,14 +94,16 @@ pub(crate) fn cmd_prev(
         [target] => target,
         [] => {
             return Err(user_error(format!(
-                "No ancestor found {offset} commit{} back",
-                if offset > 1 { "s" } else { "" }
+                "No ancestor found {} commit{} back",
+                args.offset,
+                if args.offset > 1 { "s" } else { "" }
             )))
         }
         commits => choose_commit(ui, &workspace_command, "prev", commits)?,
     };
+
     // Generate a short commit hash, to make it readable in the op log.
-    let current_short = short_commit_hash(current_wc.id());
+    let current_short = short_commit_hash(current_wc_id);
     let target_short = short_commit_hash(target.id());
     // If we're editing, just move to the revision directly.
     if edit {
diff --git a/cli/tests/test_next_prev_commands.rs b/cli/tests/test_next_prev_commands.rs
index 91ee0dacc0..4463b3fed3 100644
--- a/cli/tests/test_next_prev_commands.rs
+++ b/cli/tests/test_next_prev_commands.rs
@@ -132,21 +132,128 @@ fn test_next_exceeding_history() {
     "###);
 }
 
+// The working copy commit is a child of a "fork" with two children on each
+// branch.
 #[test]
-fn test_next_fails_on_merge_commit() {
+fn test_next_parent_has_multiple_descendants() {
     let test_env = TestEnvironment::default();
     test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
     let repo_path = test_env.env_root().join("repo");
-    test_env.jj_cmd_ok(&repo_path, &["branch", "c", "left"]);
-    test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "first"]);
-    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
-    test_env.jj_cmd_ok(&repo_path, &["branch", "c", "right"]);
-    test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "second"]);
-    test_env.jj_cmd_ok(&repo_path, &["new", "left", "right"]);
-    // Try to advance the working copy commit.
-    let stderr = test_env.jj_cmd_failure(&repo_path, &["next"]);
+    // Setup.
+    test_env.jj_cmd_ok(&repo_path, &["desc", "-m", "1"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "-m", "2"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "root()", "-m", "3"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "-m", "4"]);
+    test_env.jj_cmd_ok(&repo_path, &["edit", "description(3)"]);
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    ◉  mzvwutvlkqwt 4
+    @  zsuskulnrvyr 3
+    │ ◉  kkmpptxzrspx 2
+    │ ◉  qpvuntsmwlqt 1
+    ├─╯
+    ◉  zzzzzzzzzzzz
+    "###);
+
+    // --edit is implied since the working copy isn't a leaf commit.
+    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["next"]);
+    insta::assert_snapshot!(stdout,@r###""###);
     insta::assert_snapshot!(stderr,@r###"
-    Error: Cannot run `jj next` on a merge commit
+    Working copy now at: mzvwutvl 1b8531ce (empty) 4
+    Parent commit      : zsuskuln b1394455 (empty) 3
+    "###);
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    @  mzvwutvlkqwt 4
+    ◉  zsuskulnrvyr 3
+    │ ◉  kkmpptxzrspx 2
+    │ ◉  qpvuntsmwlqt 1
+    ├─╯
+    ◉  zzzzzzzzzzzz
+    "###);
+}
+
+#[test]
+fn test_next_with_merge_commit_parent() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+    // Setup.
+    test_env.jj_cmd_ok(&repo_path, &["desc", "-m", "1"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "root()", "-m", "2"]);
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &["new", "description(1)", "description(2)", "-m", "3"],
+    );
+    test_env.jj_cmd_ok(&repo_path, &["new", "-m", "4"]);
+    test_env.jj_cmd_ok(&repo_path, &["prev", "0"]);
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    @  royxmykxtrkr
+    │ ◉  mzvwutvlkqwt 4
+    ├─╯
+    ◉    zsuskulnrvyr 3
+    ├─╮
+    │ ◉  kkmpptxzrspx 2
+    ◉ │  qpvuntsmwlqt 1
+    ├─╯
+    ◉  zzzzzzzzzzzz
+    "###);
+
+    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["next"]);
+    insta::assert_snapshot!(stdout,@r###""###);
+    insta::assert_snapshot!(stderr,@r###"
+    Working copy now at: vruxwmqv 718bbcd9 (empty) (no description set)
+    Parent commit      : mzvwutvl cb5881ec (empty) 4
+    "###);
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    @  vruxwmqvtpmx
+    ◉  mzvwutvlkqwt 4
+    ◉    zsuskulnrvyr 3
+    ├─╮
+    │ ◉  kkmpptxzrspx 2
+    ◉ │  qpvuntsmwlqt 1
+    ├─╯
+    ◉  zzzzzzzzzzzz
+    "###);
+}
+
+#[test]
+fn test_next_on_merge_commit() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+    // Setup.
+    test_env.jj_cmd_ok(&repo_path, &["desc", "-m", "1"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "root()", "-m", "2"]);
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &["new", "description(1)", "description(2)", "-m", "3"],
+    );
+    test_env.jj_cmd_ok(&repo_path, &["new", "-m", "4"]);
+    test_env.jj_cmd_ok(&repo_path, &["edit", "description(3)"]);
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    ◉  mzvwutvlkqwt 4
+    @    zsuskulnrvyr 3
+    ├─╮
+    │ ◉  kkmpptxzrspx 2
+    ◉ │  qpvuntsmwlqt 1
+    ├─╯
+    ◉  zzzzzzzzzzzz
+    "###);
+
+    // --edit is implied since the working copy is not a leaf commit.
+    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["next"]);
+    insta::assert_snapshot!(stdout,@r###""###);
+    insta::assert_snapshot!(stderr,@r###"
+    Working copy now at: mzvwutvl cb5881ec (empty) 4
+    Parent commit      : zsuskuln 038acb86 (empty) 3
+    "###);
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    @  mzvwutvlkqwt 4
+    ◉    zsuskulnrvyr 3
+    ├─╮
+    │ ◉  kkmpptxzrspx 2
+    ◉ │  qpvuntsmwlqt 1
+    ├─╯
+    ◉  zzzzzzzzzzzz
     "###);
 }
 
@@ -228,7 +335,7 @@ fn test_next_choose_branching_child() {
 }
 
 #[test]
-fn test_prev_fails_on_merge_commit() {
+fn test_prev_on_merge_commit() {
     let test_env = TestEnvironment::default();
     test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
     let repo_path = test_env.env_root().join("repo");
@@ -248,10 +355,86 @@ fn test_prev_fails_on_merge_commit() {
     ◉  zzzzzzzzzzzz
     "###);
 
-    // Try to advance the working copy commit.
-    let stderr = test_env.jj_cmd_failure(&repo_path, &["prev"]);
+    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["prev"]);
+    insta::assert_snapshot!(stdout, @"");
+    insta::assert_snapshot!(stderr,@r###"
+    Working copy now at: vruxwmqv 41658cf4 (empty) (no description set)
+    Parent commit      : zzzzzzzz 00000000 (empty) (no description set)
+    "###);
+
+    test_env.jj_cmd_ok(&repo_path, &["undo"]);
+    let (stdout, stderr) = test_env.jj_cmd_stdin_ok(&repo_path, &["prev", "--edit"], "2\n");
+    insta::assert_snapshot!(stdout, @r###"
+    ambiguous prev commit, choose one to target:
+    1: zsuskuln b0d21db3 right | (empty) second
+    2: qpvuntsm 69542c19 left | (empty) first
+    q: quit the prompt
+    enter the index of the commit you want to target: 
+    "###);
+    insta::assert_snapshot!(stderr,@r###"
+    Working copy now at: qpvuntsm 69542c19 left | (empty) first
+    Parent commit      : zzzzzzzz 00000000 (empty) (no description set)
+    "###);
+}
+
+#[test]
+fn test_prev_on_merge_commit_with_parent_merge() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+    test_env.jj_cmd_ok(&repo_path, &["desc", "-m", "x"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "root()", "-m", "y"]);
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &["new", "description(x)", "description(y)", "-m", "z"],
+    );
+    test_env.jj_cmd_ok(&repo_path, &["new", "root()", "-m", "1"]);
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &["new", "description(z)", "description(1)", "-m", "M"],
+    );
+
+    // Check that the graph looks the way we expect.
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    @    royxmykxtrkr M
+    ├─╮
+    │ ◉  mzvwutvlkqwt 1
+    ◉ │    zsuskulnrvyr z
+    ├───╮
+    │ │ ◉  kkmpptxzrspx y
+    │ ├─╯
+    ◉ │  qpvuntsmwlqt x
+    ├─╯
+    ◉  zzzzzzzzzzzz
+    "###);
+
+    let (stdout, stderr) = test_env.jj_cmd_stdin_ok(&repo_path, &["prev"], "2\n");
+    insta::assert_snapshot!(stdout, @r###"
+    ambiguous prev commit, choose one to target:
+    1: kkmpptxz 146d5c67 (empty) y
+    2: qpvuntsm c56e5035 (empty) x
+    3: zzzzzzzz 00000000 (empty) (no description set)
+    q: quit the prompt
+    enter the index of the commit you want to target: 
+    "###);
+    insta::assert_snapshot!(stderr,@r###"
+    Working copy now at: vruxwmqv e8ff4fa0 (empty) (no description set)
+    Parent commit      : qpvuntsm c56e5035 (empty) x
+    "###);
+
+    test_env.jj_cmd_ok(&repo_path, &["undo"]);
+    let (stdout, stderr) = test_env.jj_cmd_stdin_ok(&repo_path, &["prev", "--edit"], "2\n");
+    insta::assert_snapshot!(stdout, @r###"
+    ambiguous prev commit, choose one to target:
+    1: mzvwutvl 89b8a355 (empty) 1
+    2: zsuskuln 1ef71474 (empty) z
+    q: quit the prompt
+    enter the index of the commit you want to target: 
+    "###);
     insta::assert_snapshot!(stderr,@r###"
-    Error: Cannot run `jj prev` on a merge commit
+    Working copy now at: zsuskuln 1ef71474 (empty) z
+    Parent commit      : qpvuntsm c56e5035 (empty) x
+    Parent commit      : kkmpptxz 146d5c67 (empty) y
     "###);
 }