diff --git a/ChangeLog b/ChangeLog
index f9abcd0..467e608 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2004-09-14  Adam Jackson  <ajax@freedesktop.org>
+
+	* xcompmgr.c:
+	Bug #1360: Fix a segfault by checking the return value of XQueryTree.
+	(Johan Kiviniemi)
+
 2004-09-10  Adam Jackson  <ajax@freedesktop.org>
 
 	* xcompmgr.c:
diff --git a/xcompmgr.c b/xcompmgr.c
index 122d8b4..7e542fe 100644
--- a/xcompmgr.c
+++ b/xcompmgr.c
@@ -1297,7 +1297,13 @@ determine_wintype (Display *dpy, Window w)
     if (type != winNormalAtom)
 	return type;
 
-    XQueryTree (dpy, w, &root_return, &parent_return, &children, &nchildren);
+    if (!XQueryTree (dpy, w, &root_return, &parent_return, &children,
+			    &nchildren))
+    {
+	/* XQueryTree failed. */
+	return winNormalAtom;
+    }
+
     for (i = 0;i < nchildren;i++)
     {
 	type = determine_wintype (dpy, children[i]);