diff --git a/hw/kdrive/ephyr/ephyr.c b/hw/kdrive/ephyr/ephyr.c
index ee91e47f01..556ae65254 100644
--- a/hw/kdrive/ephyr/ephyr.c
+++ b/hw/kdrive/ephyr/ephyr.c
@@ -973,6 +973,9 @@ screen_from_window(Window w)
     return NULL;
 }
 
+static void
+ephyrProcessErrorEvent(xcb_generic_event_t *xev) _X_NORETURN;
+
 static void
 ephyrProcessErrorEvent(xcb_generic_event_t *xev)
 {