diff --git a/CHANGELOG.md b/CHANGELOG.md
index cf3b773b9..759b5120d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,11 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   many people to be negatively affected, because running `jj undo` twice was
   previously a no-op.
 
+* `jj git fetch` will now only fetch the refspec patterns configured on remotes
+  when the `--bookmark` option is omitted. Only simple refspec patterns
+  are currently supported, and anything else (like refspecs which rename
+  branches) will be ignored.
+
 ### Deprecations
 
 * The on-disk index format has changed. `jj` will write index files in both old
diff --git a/cli/src/commands/git/fetch.rs b/cli/src/commands/git/fetch.rs
index e41b9045a..4aba19055 100644
--- a/cli/src/commands/git/fetch.rs
+++ b/cli/src/commands/git/fetch.rs
@@ -19,7 +19,11 @@ use itertools::Itertools as _;
 use jj_lib::config::ConfigGetResultExt as _;
 use jj_lib::git;
 use jj_lib::git::GitFetch;
+use jj_lib::git::IgnoredRefspec;
+use jj_lib::git::IgnoredRefspecs;
+use jj_lib::git::expand_default_fetch_refspecs;
 use jj_lib::git::expand_fetch_refspecs;
+use jj_lib::git::get_git_backend;
 use jj_lib::ref_name::RemoteName;
 use jj_lib::repo::Repo as _;
 use jj_lib::str_util::StringPattern;
@@ -51,7 +55,6 @@ pub struct GitFetchArgs {
     #[arg(
         long, short,
         alias = "bookmark",
-        default_value = "glob:*",
         value_parser = StringPattern::parse,
         add = ArgValueCandidates::new(complete::bookmarks),
     )]
@@ -126,44 +129,40 @@ pub fn cmd_git_fetch(
         .sorted()
         .collect_vec();
 
-    let branches_by_remote: Vec<(&RemoteName, Vec<StringPattern>)> = if args.tracked {
-        remotes
-            .iter()
-            .map(|&remote| {
-                let tracked_branches = workspace_command
-                    .repo()
-                    .view()
-                    .local_remote_bookmarks(remote)
-                    .filter(|(_, targets)| targets.remote_ref.is_tracked())
-                    .map(|(name, _)| StringPattern::exact(name))
-                    .collect_vec();
-                (remote, tracked_branches)
-            })
-            .collect_vec()
+    let mut tx = workspace_command.start_transaction();
+
+    let mut expansions = Vec::with_capacity(remotes.len());
+    if args.tracked {
+        for remote in &remotes {
+            let tracked_branches = tx
+                .repo()
+                .view()
+                .local_remote_bookmarks(remote)
+                .filter(|(_, targets)| targets.remote_ref.is_tracked())
+                .map(|(name, _)| StringPattern::exact(name))
+                .collect_vec();
+            expansions.push((remote, expand_fetch_refspecs(remote, tracked_branches)?));
+        }
+    } else if args.branch.is_empty() {
+        let git_repo = get_git_backend(tx.repo_mut().store())?.git_repo();
+        for remote in &remotes {
+            let (ignored, expanded) = expand_default_fetch_refspecs(remote, &git_repo)?;
+            warn_ignored_refspecs(ui, remote, ignored)?;
+            expansions.push((remote, expanded));
+        }
     } else {
-        remotes
-            .iter()
-            .map(|&remote| (remote, args.branch.clone()))
-            .collect_vec()
+        for remote in &remotes {
+            let expanded = expand_fetch_refspecs(remote, args.branch.clone())?;
+            expansions.push((remote, expanded));
+        }
     };
 
-    let mut tx = workspace_command.start_transaction();
     let git_settings = tx.settings().git_settings()?;
     let mut git_fetch = GitFetch::new(tx.repo_mut(), &git_settings)?;
 
-    for (remote, branches) in branches_by_remote {
-        // Skip remotes with no branches to fetch
-        if branches.is_empty() {
-            continue;
-        }
+    for (remote, expanded) in expansions {
         with_remote_git_callbacks(ui, |callbacks| {
-            git_fetch.fetch(
-                remote,
-                expand_fetch_refspecs(remote, branches)?,
-                callbacks,
-                None,
-                None,
-            )
+            git_fetch.fetch(remote, expanded, callbacks, None, None)
         })?;
     }
 
@@ -251,3 +250,19 @@ fn warn_if_branches_not_found(
 
     Ok(())
 }
+
+fn warn_ignored_refspecs(
+    ui: &Ui,
+    remote_name: &RemoteName,
+    IgnoredRefspecs(ignored_refspecs): IgnoredRefspecs,
+) -> Result<(), CommandError> {
+    let remote_name = remote_name.as_symbol();
+    for IgnoredRefspec { refspec, reason } in ignored_refspecs {
+        writeln!(
+            ui.warning_default(),
+            "Ignored refspec `{refspec}` from `{remote_name}`: {reason}",
+        )?;
+    }
+
+    Ok(())
+}
diff --git a/cli/src/commands/git/mod.rs b/cli/src/commands/git/mod.rs
index 903a7e7cc..274778b23 100644
--- a/cli/src/commands/git/mod.rs
+++ b/cli/src/commands/git/mod.rs
@@ -21,6 +21,7 @@ mod push;
 mod remote;
 mod root;
 
+use std::io::Write as _;
 use std::path::Path;
 
 use clap::Subcommand;
diff --git a/cli/tests/cli-reference@.md.snap b/cli/tests/cli-reference@.md.snap
index f78cdc615..30cd7b7b9 100644
--- a/cli/tests/cli-reference@.md.snap
+++ b/cli/tests/cli-reference@.md.snap
@@ -1259,8 +1259,6 @@ If a working-copy commit gets abandoned, it will be given a new, empty commit. T
 * `-b`, `--branch <BRANCH>` — Fetch only some of the branches
 
    By default, the specified name matches exactly. Use `glob:` prefix to expand `*` as a glob, e.g. `--branch 'glob:push-*'`. Other wildcard characters such as `?` are *not* supported. Can be repeated to specify multiple branches.
-
-  Default value: `glob:*`
 * `--tracked` — Fetch only tracked bookmarks
 
    This fetches only bookmarks that are already tracked from the specified remote(s).
diff --git a/cli/tests/test_git_fetch.rs b/cli/tests/test_git_fetch.rs
index 4ac7162bf..76182236c 100644
--- a/cli/tests/test_git_fetch.rs
+++ b/cli/tests/test_git_fetch.rs
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::io::Write as _;
+
 use testutils::git;
 
 use crate::common::CommandOutput;
@@ -228,6 +230,54 @@ fn test_git_fetch_multiple_remotes() {
     ");
 }
 
+#[test]
+fn test_git_fetch_with_ignored_refspecs() {
+    let test_env = TestEnvironment::default();
+    test_env.add_config("git.auto-local-bookmark = true");
+    test_env
+        .run_jj_in(".", ["git", "init", "--colocate", "repo"])
+        .success();
+    let source_repo = init_git_remote(&test_env, "origin");
+
+    for branch in ["main", "foo", "foobar", "foobaz", "bar"] {
+        add_commit_to_branch(&source_repo, &format!("refs/heads/{branch}"), branch);
+    }
+
+    let work_dir = test_env.work_dir("repo");
+    std::fs::OpenOptions::new()
+        .append(true)
+        .open(work_dir.root().join("./.git/config"))
+        .expect("failed to open config file")
+        .write_all(
+            br#"
+            [remote "origin"]
+            url = ../origin/.git
+            fetch = +refs/heads/main:refs/remotes/origin/main
+            fetch = +refs/heads/foo*:refs/remotes/origin/baz*
+            fetch = +refs/heads/bar*:refs/tags/bar*
+            fetch = refs/heads/bar
+            "#,
+        )
+        .expect("failed to update config file");
+
+    let output = work_dir.run_jj(["git", "fetch"]).success();
+
+    insta::assert_snapshot!(output.stdout, @r"");
+    insta::assert_snapshot!(output.stderr, @r"
+    Warning: Ignored refspec `refs/heads/bar` from `origin`: fetch-only refspecs are not supported
+    Warning: Ignored refspec `+refs/heads/bar*:refs/tags/bar*` from `origin`: only refs/remotes/ is supported for fetch destinations
+    Warning: Ignored refspec `+refs/heads/foo*:refs/remotes/origin/baz*` from `origin`: renaming is not supported
+    bookmark: main@origin [new] tracked
+    [EOF]
+    ");
+    insta::assert_snapshot!(get_bookmark_output(&work_dir), @r"
+    main: kpukqsrq f803461e main
+      @git: kpukqsrq f803461e main
+      @origin: kpukqsrq f803461e main
+    [EOF]
+    ");
+}
+
 #[test]
 fn test_git_fetch_with_glob() {
     let test_env = TestEnvironment::default();