diff --git a/ctf/flagd.py b/ctf/flagd.py
index 6ae444b..f827972 100755
--- a/ctf/flagd.py
+++ b/ctf/flagd.py
@@ -142,6 +142,8 @@ class FlagServer(asynchat.async_chat):
         self.inbuf.append(data)
 
     def set_flag(self, team):
+        if not self.cat:
+            return
         self.flag = team
         self.submitter.set_flag(self.cat, team)
         f = open(os.path.join(flags_dir, self.cat), 'w')
diff --git a/pwnables/Makefile b/pwnables/Makefile
index 7eca8ef..5327560 100644
--- a/pwnables/Makefile
+++ b/pwnables/Makefile
@@ -18,4 +18,4 @@ target:
 	$(MAKE) -C daemons TARGET=$(TARGET) install
 
 clean:
-	rm -rf target
+	rm -rf target pwnables.tce
diff --git a/pwnables/skel/usr/lib/www/flag b/pwnables/skel/usr/lib/www/flag
new file mode 120000
index 0000000..f4bdb9f
--- /dev/null
+++ b/pwnables/skel/usr/lib/www/flag
@@ -0,0 +1 @@
+/var/lib/cat/flag
\ No newline at end of file