--- a/src/gtk+-2.x/ctkvdpau.c
+++ b/src/gtk+-2.x/ctkvdpau.c
@@ -103,6 +103,8 @@
 const gchar* __video_mixer_attribute_help =
 "This shows the video mixer attributes and any applicable ranges.";
 
+struct VDPAUDeviceImpl VDPAUDeviceFunctions;
+
 static int queryOutputSurface(CtkVDPAU *ctk_vdpau, VdpDevice device,
                               VdpGetProcAddress *getProcAddress);
 
--- a/src/gtk+-2.x/ctkvdpau.h
+++ b/src/gtk+-2.x/ctkvdpau.h
@@ -46,7 +46,7 @@
     (G_TYPE_INSTANCE_GET_CLASS ((obj), CTK_TYPE_VDPAU, CtkVDPAUClass))
 
 
-struct VDPAUDeviceImpl {
+extern struct VDPAUDeviceImpl {
 
     VdpGetErrorString *GetErrorString;
     VdpGetProcAddress *GetProcAddress;