diff --git a/Machines/Atari/ST/IntelligentKeyboard.cpp b/Machines/Atari/ST/IntelligentKeyboard.cpp
index 38ee5badd..66b31b557 100644
--- a/Machines/Atari/ST/IntelligentKeyboard.cpp
+++ b/Machines/Atari/ST/IntelligentKeyboard.cpp
@@ -61,9 +61,9 @@ void IntelligentKeyboard::run_for(HalfCycles duration) {
 				(abs(captured_movement[0]) >= mouse_threshold_[0]) ||
 				(abs(captured_movement[1]) >= mouse_threshold_[1]) ) {
 				mouse_movement_[0] -= captured_movement[0];
-				mouse_movement_[1] -= mouse_y_multiplier_ * captured_movement[1];
+				mouse_movement_[1] -= captured_movement[1];
 
-				post_relative_mouse_event(captured_movement[0], captured_movement[1]);
+				post_relative_mouse_event(captured_movement[0], captured_movement[1] * mouse_y_multiplier_);
 			}
 		} break;
 
diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme b/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme
index 1465a4f62..47f9c7286 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme	
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme	
@@ -67,7 +67,7 @@
       </Testables>
    </TestAction>
    <LaunchAction
-      buildConfiguration = "Release"
+      buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       enableASanStackUseAfterReturn = "YES"