diff --git a/mousetrap/mousetrap.d.ts b/mousetrap/mousetrap.d.ts
index 814efb3dd..d2ae42aa6 100644
--- a/mousetrap/mousetrap.d.ts
+++ b/mousetrap/mousetrap.d.ts
@@ -4,11 +4,11 @@
 // Definitions: https://github.com/borisyankov/DefinitelyTyped
 
 interface ExtendedKeyboardEvent extends KeyboardEvent {
-    returnValue: bool; // IE returnValue
+    returnValue: boolean; // IE returnValue
 }
 
 interface MousetrapStatic {
-    stopCallback: (e: ExtendedKeyboardEvent, element: Element, combo: string) => bool;
+    stopCallback: (e: ExtendedKeyboardEvent, element: Element, combo: string) => boolean;
 
     bind(keys: string, callback: (e: ExtendedKeyboardEvent, combo: string) => any, action?: string): void;
     bind(keyArray: string[], callback: (e: ExtendedKeyboardEvent, combo: string) => any, action?: string): void;