diff --git a/dwm.c b/dwm.c
index 965d1e3..dd39fe1 100644
--- a/dwm.c
+++ b/dwm.c
@@ -1590,7 +1590,9 @@ updatesizehints(Client *c) {
 	long msize;
 	XSizeHints size;
 
-	XGetWMNormalHints(dpy, c->win, &size, &msize);
+	if(!XGetWMNormalHints(dpy, c->win, &size, &msize))
+		/* size is uninitialized, ensure that size.flags aren't used */
+		size.flags = PSize; 
 	if(size.flags & PBaseSize) {
 		c->basew = size.base_width;
 		c->baseh = size.base_height;