diff --git a/cli/tests/test_working_copy.rs b/cli/tests/test_working_copy.rs
index a45d4f506..14a4486fc 100644
--- a/cli/tests/test_working_copy.rs
+++ b/cli/tests/test_working_copy.rs
@@ -20,6 +20,8 @@ fn test_snapshot_large_file() {
     test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
     let repo_path = test_env.env_root().join("repo");
 
+    // test a small file using raw-integer-literal syntax, which is interpreted
+    // in bytes
     test_env.add_config(r#"snapshot.max-new-file-size = 10"#);
     std::fs::write(repo_path.join("large"), "a lot of text").unwrap();
     let stderr = test_env.jj_cmd_failure(&repo_path, &["files"]);
@@ -33,4 +35,20 @@ fn test_snapshot_large_file() {
       - Run `jj --config-toml 'snapshot.max-new-file-size=13' st`
         This will increase the maximum file size allowed for new files, for this command only.
     "###);
+
+    // test with a larger file using 'KB' human-readable syntax
+    test_env.add_config(r#"snapshot.max-new-file-size = "10KB""#);
+    let big_string = vec![0; 1024 * 11];
+    std::fs::write(repo_path.join("large"), big_string).unwrap();
+    let stderr = test_env.jj_cmd_failure(&repo_path, &["files"]);
+    insta::assert_snapshot!(stderr, @r###"
+    Error: Failed to snapshot the working copy
+    The file '$TEST_ENV/repo/large' is too large to be snapshotted: it is 1024 bytes too large; the maximum size allowed is 10240 bytes (10.0KiB).
+    Hint: This is to prevent large files from being added on accident. You can fix this error by:
+      - Adding the file to `.gitignore`
+      - Run `jj config set --repo snapshot.max-new-file-size 11264`
+        This will increase the maximum file size allowed for new files, in this repository only.
+      - Run `jj --config-toml 'snapshot.max-new-file-size=11264' st`
+        This will increase the maximum file size allowed for new files, for this command only.
+    "###);
 }