diff --git a/packages/melonjs/src/input/gamepad.ts b/packages/melonjs/src/input/gamepad.ts
index 18c7503fe..f83fef9fc 100644
--- a/packages/melonjs/src/input/gamepad.ts
+++ b/packages/melonjs/src/input/gamepad.ts
@@ -20,7 +20,7 @@ interface ButtonBinding {
 	keyCode: number;
 	value: number;
 	pressed: boolean;
-	threshold?: number;
+	threshold?: number | undefined;
 }
 
 interface GamepadBindings {
diff --git a/packages/tsconfig/base.json b/packages/tsconfig/base.json
index f2204134b..fa3ee9513 100644
--- a/packages/tsconfig/base.json
+++ b/packages/tsconfig/base.json
@@ -17,6 +17,7 @@
 		"strictPropertyInitialization": false,
 		"allowImportingTsExtensions": true,
 		"noUnusedParameters": true,
-		"noImplicitOverride": true
+		"noImplicitOverride": true,
+		"exactOptionalPropertyTypes": true
 	}
 }