diff --git a/data/src/emulator.js b/data/src/emulator.js
index 79e4b61..c6ff7a2 100644
--- a/data/src/emulator.js
+++ b/data/src/emulator.js
@@ -3053,7 +3053,7 @@ class EmulatorJS {
                                     this.gameManager.simulateInput(i, 22, 0x7fff * e.value);
                                     this.gameManager.simulateInput(i, 23, 0);
                                 } else {
-                                    this.gameManager.simulateInput(i, 23, 0x7fff * e.value);
+                                    this.gameManager.simulateInput(i, 23, -0x7fff * e.value);
                                     this.gameManager.simulateInput(i, 22, 0);
                                 }
                             }