diff --git a/KeyboardioFirmware.h b/KeyboardioFirmware.h
index 4ac048d9..ddec1e6d 100644
--- a/KeyboardioFirmware.h
+++ b/KeyboardioFirmware.h
@@ -70,7 +70,6 @@ void send_key_events();
 void handle_key_event(byte row, byte col);
 void press_key(Key mappedKey);
 
-int setup_sx1509(sx1509Class sx1509, uint8_t colpins[], uint8_t rowpins[]);
 
 #ifndef VERSION
 #define VERSION "locally-built"