diff --git a/Cargo.lock b/Cargo.lock
index 3da0d8ca455..c576dbfc184 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1699,6 +1699,7 @@ dependencies = [
  "pest",
  "pest_derive",
  "pollster",
+ "rand",
  "regex",
  "rpassword",
  "scm-record",
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 1444902a565..49f09d06519 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -58,6 +58,7 @@ once_cell = { workspace = true }
 pest = { workspace = true }
 pest_derive = { workspace = true }
 pollster = { workspace = true }
+rand = { workspace = true }
 regex = { workspace = true }
 rpassword = { workspace = true }
 scm-record = { workspace = true }
diff --git a/cli/tests/test_working_copy.rs b/cli/tests/test_working_copy.rs
index a7bacea3436..054c15295cd 100644
--- a/cli/tests/test_working_copy.rs
+++ b/cli/tests/test_working_copy.rs
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use rand::Rng;
+
 use crate::common::TestEnvironment;
 
 #[test]
@@ -34,4 +36,22 @@ fn test_snapshot_large_file() {
       - Run `jj --config-toml 'snapshot.max-new-file-size="13B"' 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 mut big_string = vec![0; 1024 * 11];
+    rand::thread_rng().fill(&mut big_string[..]);
+    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 (11264 bytes).
+    The maximum size allowed is 10240 bytes.
+    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 "11264B"`
+        This will increase the maximum file size allowed for new files, in this repository only.
+      - Run `jj --config-toml 'snapshot.max-new-file-size="11264B"' st`
+        This will increase the maximum file size allowed for new files, for this command only.
+    "###);
 }