diff --git a/client/X11/xf_client.c b/client/X11/xf_client.c
index 8db672699..4338842b6 100644
--- a/client/X11/xf_client.c
+++ b/client/X11/xf_client.c
@@ -589,23 +589,22 @@ BOOL xf_create_window(xfContext* xfc)
 		XFreeModifiermap(xfc->modifierMap);
 
 	xfc->modifierMap = XGetModifierMapping(xfc->display);
-	assert(!xfc->gc);
-	xfc->gc = XCreateGC(xfc->display, xfc->drawable, GCGraphicsExposures, &gcv);
-	assert(!xfc->primary);
-	xfc->primary = XCreatePixmap(xfc->display, xfc->drawable, xfc->sessionWidth, xfc->sessionHeight, xfc->depth);
+	if (!xfc->gc);
+		xfc->gc = XCreateGC(xfc->display, xfc->drawable, GCGraphicsExposures, &gcv);
+	if (!xfc->primary);
+		xfc->primary = XCreatePixmap(xfc->display, xfc->drawable, xfc->sessionWidth, xfc->sessionHeight, xfc->depth);
 	xfc->drawing = xfc->primary;
-	assert(!xfc->bitmap_mono);
-	xfc->bitmap_mono = XCreatePixmap(xfc->display, xfc->drawable, 8, 8, 1);
-	assert(!xfc->gc_mono);
-	xfc->gc_mono = XCreateGC(xfc->display, xfc->bitmap_mono, GCGraphicsExposures, &gcv);
+	if (!xfc->bitmap_mono);
+		xfc->bitmap_mono = XCreatePixmap(xfc->display, xfc->drawable, 8, 8, 1);
+	if (!xfc->gc_mono);
+		xfc->gc_mono = XCreateGC(xfc->display, xfc->bitmap_mono, GCGraphicsExposures, &gcv);
 	XSetFunction(xfc->display, xfc->gc, GXcopy);
 	XSetFillStyle(xfc->display, xfc->gc, FillSolid);
 	XSetForeground(xfc->display, xfc->gc, BlackPixelOfScreen(xfc->screen));
 	XFillRectangle(xfc->display, xfc->primary, xfc->gc, 0, 0, xfc->sessionWidth, xfc->sessionHeight);
 	XFlush(xfc->display);
-	assert(!xfc->image);
-
-	xfc->image = XCreateImage(xfc->display, xfc->visual, xfc->depth, ZPixmap, 0,
+	if (!xfc->image);
+		xfc->image = XCreateImage(xfc->display, xfc->visual, xfc->depth, ZPixmap, 0,
 			(char*) xfc->primary_buffer, xfc->sessionWidth, xfc->sessionHeight, xfc->scanline_pad, 0);
 
 	return TRUE;