diff --git a/src/command/cmd.rs b/src/command/cmd.rs
index 6a2e96d..c09ff38 100644
--- a/src/command/cmd.rs
+++ b/src/command/cmd.rs
@@ -1632,7 +1632,7 @@ impl Cmd for ExecuteCommand {
                     effects.extend(cmd.execute(ctx));
                 }
                 // Return to Normal unless a command already changed mode
-                if !effects.iter().any(|e| format!("{e:?}").contains("ChangeMode")) {
+                if !effects.iter().any(|e| e.changes_mode()) {
                     effects.push(effect::change_mode(AppMode::Normal));
                 }
                 effects
@@ -2955,10 +2955,9 @@ mod tests {
         ctx.buffers = &bufs;
         let cmd = ExecuteCommand;
         let effects = cmd.execute(&ctx);
-        let dbg = format!("{:?}", effects);
         assert!(
-            dbg.contains("ChangeMode"),
-            "Expected ChangeMode, got: {dbg}"
+            effects.iter().any(|e| e.changes_mode()),
+            "Expected a mode-changing effect"
         );
     }
 
diff --git a/src/ui/effect.rs b/src/ui/effect.rs
index f141291..7186095 100644
--- a/src/ui/effect.rs
+++ b/src/ui/effect.rs
@@ -10,6 +10,10 @@ use super::app::{App, AppMode};
 /// Effects know how to apply themselves to the App.
 pub trait Effect: Debug {
     fn apply(&self, app: &mut App);
+    /// Whether this effect changes the app mode.
+    fn changes_mode(&self) -> bool {
+        false
+    }
 }
 
 // ── Model mutations ──────────────────────────────────────────────────────────
@@ -328,6 +332,9 @@ impl Effect for ChangeMode {
     fn apply(&self, app: &mut App) {
         app.mode = self.0.clone();
     }
+    fn changes_mode(&self) -> bool {
+        true
+    }
 }
 
 #[derive(Debug)]