diff --git a/libmproxy/proxy.py b/libmproxy/proxy.py
index e7b2c409a..0d1ad6924 100644
--- a/libmproxy/proxy.py
+++ b/libmproxy/proxy.py
@@ -423,7 +423,11 @@ class AppRegistry:
         """
             Returns an WSGIAdaptor instance if request matches an app, or None.
         """
-        return self.apps.get((request.host, request.port), None)
+        if (request.host, request.port) in self.apps:
+            return self.apps[(request.host, request.port)]
+        if "host" in request.headers:
+            host = request.headers["host"][0]
+            return self.apps.get((host, request.port), None)
 
 
 class DummyServer:
diff --git a/test/test_proxy.py b/test/test_proxy.py
index d4d275b5a..105871689 100644
--- a/test/test_proxy.py
+++ b/test/test_proxy.py
@@ -21,3 +21,11 @@ def test_app_registry():
 
     r.port = 81
     assert not ar.get(r)
+
+
+    r = tutils.treq()
+    r.host = "domain2"
+    r.port = 80
+    assert not ar.get(r)
+    r.headers["host"] = ["domain"]
+    assert ar.get(r)