diff --git a/termwiz/src/escape/mod.rs b/termwiz/src/escape/mod.rs
index 52e705cc7..4bb0a52b4 100644
--- a/termwiz/src/escape/mod.rs
+++ b/termwiz/src/escape/mod.rs
@@ -45,6 +45,16 @@ pub enum Action {
     KittyImage(KittyImage),
 }
 
+#[cfg(all(test, target_pointer_width = "64"))]
+#[test]
+fn action_size() {
+    assert_eq!(std::mem::size_of::<Action>(), 184);
+    assert_eq!(std::mem::size_of::<DeviceControlMode>(), 16);
+    assert_eq!(std::mem::size_of::<ControlCode>(), 1);
+    assert_eq!(std::mem::size_of::<CSI>(), 48);
+    assert_eq!(std::mem::size_of::<Esc>(), 4);
+}
+
 /// Encode self as an escape sequence.  The escape sequence may potentially
 /// be clear text with no actual escape sequences.
 impl Display for Action {