diff --git a/libmproxy/utils.py b/libmproxy/utils.py
index f3c36f8f8..165404348 100644
--- a/libmproxy/utils.py
+++ b/libmproxy/utils.py
@@ -422,7 +422,7 @@ def parse_url(url):
 
 def parse_proxy_spec(url):
     p = parse_url(url)
-    if not p:
+    if not p or not p[1]:
         return None
     return p[:3]
 
diff --git a/test/test_utils.py b/test/test_utils.py
index 90585194c..510dbd597 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -206,6 +206,7 @@ class u_parse_proxy_spec(libpry.AutoTree):
         assert utils.parse_proxy_spec("http://foo.com:88") == ("http", "foo.com", 88)
         assert utils.parse_proxy_spec("http://foo.com") == ("http", "foo.com", 80)
         assert not utils.parse_proxy_spec("foo.com") 
+        assert not utils.parse_proxy_spec("http://") 
 
 
 class u_unparse_url(libpry.AutoTree):