diff --git a/stepmania/src/InputFilter.cpp b/stepmania/src/InputFilter.cpp
index d09efc0617..41e7d51320 100644
--- a/stepmania/src/InputFilter.cpp
+++ b/stepmania/src/InputFilter.cpp
@@ -332,7 +332,7 @@ void InputFilter::GetInputEvents( vector<InputEvent> &array )
 	array.swap( queue );
 }
 
-void InputFilter::GetPressedButtons( vector<DeviceInput> &array )
+void InputFilter::GetPressedButtons( vector<DeviceInput> &array ) const
 {
 	LockMut(*queuemutex);
 	array = g_CurrentState;
diff --git a/stepmania/src/InputFilter.h b/stepmania/src/InputFilter.h
index 7a5c96fe4b..fce00613c4 100644
--- a/stepmania/src/InputFilter.h
+++ b/stepmania/src/InputFilter.h
@@ -54,7 +54,7 @@ public:
 	RString GetButtonComment( const DeviceInput &di ) const;
 	
 	void GetInputEvents( vector<InputEvent> &aEventOut );
-	void GetPressedButtons( vector<DeviceInput> &array );
+	void GetPressedButtons( vector<DeviceInput> &array ) const;
 
 private:
 	void CheckButtonChange( ButtonState &bs, DeviceInput di, const RageTimer &now );