diff --git a/crates/benilla-app/src/bindings.rs b/crates/benilla-app/src/bindings.rs
index eb2e5c8b..fc5c3d02 100644
--- a/crates/benilla-app/src/bindings.rs
+++ b/crates/benilla-app/src/bindings.rs
@@ -899,6 +899,52 @@ mod tests {
             .expect("eval")
     }
 
+    /// A **chorded** registry `EdgeUpDown` runs both halves, which is what an action button on a
+    /// modified key is.
+    ///
+    /// grom's slam macro sits on `SHIFT-1` → `MULTIACTIONBAR1BUTTON1`
+    /// (`bindings/C_Thun-Gromgosh.txt:28`), and pfUI points both `MultiActionButtonDown` and
+    /// `MultiActionButtonUp` at the same `pfActionButton` (`modules/actionbar.lua:1516-17`), so
+    /// the reference runs his macro twice per press — once on the press, once on the release —
+    /// and he reported seeing it run once. Both halves have to reach the VM for that second roll
+    /// at a 0.2 s window to exist.
+    #[test]
+    fn a_chorded_action_button_runs_both_halves() {
+        let mut script = UiScript::new().expect("VM");
+        script.register_bindings(&registry_commands());
+        script
+            .run(
+                "MULTI_DOWN = 0 MULTI_UP = 0 \
+                 function MultiActionButtonDown() MULTI_DOWN = MULTI_DOWN + 1 end \
+                 function MultiActionButtonUp() MULTI_UP = MULTI_UP + 1 end \
+                 SetBinding(\"SHIFT-1\", \"MULTIACTIONBAR1BUTTON1\")",
+            )
+            .expect("bind");
+        let mut app = vm_harness(script);
+
+        // The modifier is held across both edges, as a hand holding shift is.
+        press_key(&mut app, KeyCode::ShiftLeft);
+        app.update();
+
+        press_key(&mut app, KeyCode::Digit1);
+        app.update();
+        assert_eq!(lua_count(&app, "MULTI_DOWN"), 1, "the press half");
+        assert_eq!(lua_count(&app, "MULTI_UP"), 0, "not released yet");
+
+        release_key(&mut app, KeyCode::Digit1);
+        app.update();
+        assert_eq!(
+            lua_count(&app, "MULTI_UP"),
+            1,
+            "the release half — the second evaluation of the macro"
+        );
+        assert_eq!(
+            lua_count(&app, "MULTI_DOWN"),
+            1,
+            "and not the down half again"
+        );
+    }
+
     /// An addon's `runOnUp` body is one chunk run twice, `keystate` "down" then "up"; our own
     /// registry holds two strings ([`Kind::EdgeUpDown`]) instead.
     #[test]