diff --git a/libvo/vo_x11.c b/libvo/vo_x11.c
index 5f139287d2..2343a16f72 100644
--- a/libvo/vo_x11.c
+++ b/libvo/vo_x11.c
@@ -29,9 +29,6 @@ static int Shmem_Flag;
 static XShmSegmentInfo Shminfo[1];
 static int gXErrorFlag;
 static int CompletionType = -1;
-
-/* since it doesn't seem to be defined on some platforms */
-int XShmGetEventBase(Display *);
 #endif
 
 #include "sub.h"
diff --git a/libvo/vo_xvmc.c b/libvo/vo_xvmc.c
index 3ad41b5ac9..8e0fbbb15d 100644
--- a/libvo/vo_xvmc.c
+++ b/libvo/vo_xvmc.c
@@ -131,8 +131,6 @@ const LIBVO_EXTERN(xvmc);
 
 //shm stuff from vo_xv
 #ifdef HAVE_SHM
-/* since it doesn't seem to be defined on some platforms */
-int XShmGetEventBase(Display*);
 static XShmSegmentInfo Shminfo;
 static int Shmem_Flag;
 #endif