diff --git a/engine/gl/gl_vidlinuxglx.c b/engine/gl/gl_vidlinuxglx.c
index 67a42a8a0..1e8c7a908 100644
--- a/engine/gl/gl_vidlinuxglx.c
+++ b/engine/gl/gl_vidlinuxglx.c
@@ -64,6 +64,10 @@ int scrnum;
 
 static float old_windowed_mouse = 0;
 
+#ifdef USE_DGA
+static int dgamouse = 0;
+#endif
+
 #define KEY_MASK (KeyPressMask | KeyReleaseMask)
 #define MOUSE_MASK (ButtonPressMask | ButtonReleaseMask | \
 		    PointerMotionMask)