diff --git a/keyboards/ploopyco/trackball/trackball.h b/keyboards/ploopyco/trackball/trackball.h
index add2deb291..8452a78ee7 100644
--- a/keyboards/ploopyco/trackball/trackball.h
+++ b/keyboards/ploopyco/trackball/trackball.h
@@ -33,8 +33,6 @@
 #define OPT_ENC1_MUX 0
 #define OPT_ENC2_MUX 4
 
-void process_wheel(report_mouse_t* mouse_report);
-
 #define LAYOUT(BL, BM, BR, BF, BB) \
     { {BL, BM, BR, BF, BB}, }