diff --git a/crates/engine/src/extra_cmds.rs b/crates/engine/src/extra_cmds.rs
index 4e2a265ab9..c24f30e515 100644
--- a/crates/engine/src/extra_cmds.rs
+++ b/crates/engine/src/extra_cmds.rs
@@ -366,6 +366,13 @@ fn paste_into(s: &mut Session, p: &Value, outside: bool) -> Result<Value> {
         params["target"] = p.get("target").cloned().unwrap_or_default();
         return crate::edit_cmds::paste_to_target(s, &params, false, Some(&limit), label);
     }
+    // The pasted layer lands beside the active one, inside its group, and a Lock-All group refuses
+    // its layer mask: refuse before pasting rather than leave an unmasked paste behind.
+    let d = s.active().ok_or(EngineError::NoDocument)?;
+    let group = d.active_layer.and_then(|a| d.doc.path_of(a)).and_then(|p| d.doc.layer_at(p.split_last()?.1).map(|g| g.id));
+    if let Some(g) = group {
+        crate::commands::check_all_unlocked(&d.doc, g)?;
+    }
     let key = step_key(s, "pasteInto");
     params["coalesce"] = json!(key);
     params["target"] = json!("pixels");
diff --git a/crates/engine/tests/it/main.rs b/crates/engine/tests/it/main.rs
index cd44a7a946..874c4f5226 100644
--- a/crates/engine/tests/it/main.rs
+++ b/crates/engine/tests/it/main.rs
@@ -44,6 +44,7 @@ mod layer_mask_depth;
 mod layer_props_several;
 mod layer_range_panel_order;
 mod live_line_transform;
+mod mask_lock_all;
 mod merge_transparent_bounds;
 mod missing_layer_error;
 mod nonfinite_style;
diff --git a/crates/engine/tests/mask_lock_all.rs b/crates/engine/tests/it/mask_lock_all.rs
similarity index 68%
rename from crates/engine/tests/mask_lock_all.rs
rename to crates/engine/tests/it/mask_lock_all.rs
index f0334619f1..74ea71ff62 100644
--- a/crates/engine/tests/mask_lock_all.rs
+++ b/crates/engine/tests/it/mask_lock_all.rs
@@ -69,3 +69,24 @@ fn a_locked_layer_among_the_selected_layers_refuses_the_whole_mask() {
     assert!(s.execute("layer.layerMask.hideAll", json!({})).is_err());
     assert!(s.active().unwrap().doc.walk().iter().all(|(_, _, l)| l.mask.is_none()), "no layer got a mask");
 }
+
+#[test]
+fn paste_into_a_lock_all_group_refuses_before_pasting() {
+    for cmd in ["edit.pasteSpecial.pasteInto", "edit.pasteSpecial.pasteOutside"] {
+        let mut s = Session::new();
+        s.execute("file.new", json!({"width": 40, "height": 30})).unwrap();
+        let child = s.execute("layer.new.layer", json!({"name": "Child"})).unwrap()["layer"].as_u64().unwrap();
+        s.execute("paint.stroke", json!({"points": [[5, 10], [20, 10]], "size": 8, "hardness": 1.0, "color": "#ff0000"})).unwrap();
+        s.execute("select.all", json!({})).unwrap();
+        s.execute("edit.copy", json!({})).unwrap();
+        let group = s.execute("layer.groupLayers", json!({})).unwrap()["layer"].as_u64().unwrap();
+        s.execute("layer.setProps", json!({"layer": group, "locks": {"all": true}})).unwrap();
+        s.execute("layer.select", json!({"layer": child, "mode": "replace"})).unwrap();
+        s.execute("select.rect", json!({"x": 2, "y": 2, "width": 20, "height": 15})).unwrap();
+        let layers = s.active().unwrap().doc.walk().len();
+        let undo = undo_depth(&s);
+        assert!(s.execute(cmd, json!({})).is_err(), "{cmd}");
+        assert_eq!(s.active().unwrap().doc.walk().len(), layers, "{cmd} pasted no layer");
+        assert_eq!(undo_depth(&s), undo, "{cmd} added no history step");
+    }
+}