diff --git a/src/proto/if_python3.pro b/src/proto/if_python3.pro
index 74b2be4..c1b5916 100644
--- a/src/proto/if_python3.pro
+++ b/src/proto/if_python3.pro
@@ -3,6 +3,7 @@
 void python3_end __ARGS((void));
 int python3_loaded __ARGS((void));
 void ex_py3 __ARGS((exarg_T *eap));
+void ex_py3do __ARGS((exarg_T *eap));
 void ex_py3file __ARGS((exarg_T *eap));
 void python3_buffer_free __ARGS((buf_T *buf));
 void python3_window_free __ARGS((win_T *win));