diff --git a/acconfig.h b/acconfig.h
index 736ac74..81c6875 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -2,7 +2,9 @@
 #undef VERSION
 
 /* Define if you have the XFree86 DGA extension */
-#undef HAS_DGA
+#ifndef HAS_DGA
+#define HAS_DGA
+#endif
 
 /* If your version of OpenGL uses APIENTRY, define GLAPIENTRY to be APIENTRY*/
 #undef GLAPIENTRY
@@ -26,7 +28,9 @@
 #undef USE_BSD_CD
 
 /* Define this to use experimental code */
-#undef _EXPERIMENTAL_
+#ifndef _EXPERIMENTAL_
+#define _EXPERIMENTAL_
+#endif
 
 #if defined(X11)
 #   define OUTPUT_STR	"X11"
diff --git a/common/gl_vidglx.c b/common/gl_vidglx.c
index 9f0968d..aff4837 100644
--- a/common/gl_vidglx.c
+++ b/common/gl_vidglx.c
@@ -346,7 +346,7 @@ do_fullscreen(int full)
 		/* We are in XMesa fullscren mode and couldn't switch back
 		   to windowed mode ??? */
 		Cvar_SetValue("vid_glx_fullscreen", fullscreen);
-		do_grab(mouse_shouldgrab);
+		do_grabs(mouse_shouldgrab);
 		return;
 	}
 #endif