diff --git a/backends/x/event.go b/backends/x/event.go
index a3a8b8e..4195431 100644
--- a/backends/x/event.go
+++ b/backends/x/event.go
@@ -43,7 +43,7 @@ func (backend *Backend) handleButtonPress (
 ) {
 	buttonEvent := *event.ButtonPressEvent
 	backend.channel <- stone.EventPress {
-		Button: stone.Button(buttonEvent.Detail),
+		Button: stone.Button(buttonEvent.Detail + 127),
 	}
 }
 
@@ -53,7 +53,7 @@ func (backend *Backend) handleButtonRelease (
 ) {
 	buttonEvent := *event.ButtonReleaseEvent
 	backend.channel <- stone.EventRelease {
-		Button: stone.Button(buttonEvent.Detail),
+		Button: stone.Button(buttonEvent.Detail + 127),
 	}
 }