diff --git a/converter/adb_usb/config.h b/converter/adb_usb/config.h
index 70c5e67d..a0996d03 100644
--- a/converter/adb_usb/config.h
+++ b/converter/adb_usb/config.h
@@ -42,6 +42,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // Mouse Extended Report
 #define MOUSE_EXT_REPORT
 
+// Second button in Apple Classic Mouse protocol is ignored as Mac OS9 and OSX does.
+// Without this some of 2-button mouses are unusable.
+// https://github.com/tmk/tmk_keyboard/issues/724
+#define ADB_MOUSE_2ND_BUTTON_QUIRK
+
 
 /* ADB port setting */
 #define ADB_PORT        PORTD
diff --git a/converter/adb_usb/matrix.c b/converter/adb_usb/matrix.c
index 54ffb084..fd33aaaa 100644
--- a/converter/adb_usb/matrix.c
+++ b/converter/adb_usb/matrix.c
@@ -507,6 +507,13 @@ void adb_mouse_task(void)
         if (buf[0] & 0x40) yneg = true;
         if (buf[1] & 0x40) xneg = true;
         len = 2;
+
+        #ifdef ADB_MOUSE_2ND_BUTTON_QUIRK
+        // Ignore b01('optional second button') as OSX/MacOS9 does.
+        // Some mouses misuse the bit and make it unusable.
+        // https://github.com/tmk/tmk_keyboard/issues/724
+        buf[1] |= 0x80;
+        #endif
     }
 
     // Make unused buf bytes compatible with Extended Mouse Protocol