diff --git a/Makefile b/Makefile
index c1637acfb..b8a88d7d5 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,7 @@ all:
 	@echo "clean           -- cleanup working directory"
 
 test:
-	PYTHONPATH="${PYTHONPATH}:/" python3 -m unittest discover -s test -p "*_test.py" -b -v
+	pytest
 
 build:
 	@python3 setup.py sdist
diff --git a/test/knxip_tests/connect_response_test.py b/test/knxip_tests/connect_response_test.py
index a3ff660c8..82d748861 100644
--- a/test/knxip_tests/connect_response_test.py
+++ b/test/knxip_tests/connect_response_test.py
@@ -75,3 +75,20 @@ def test_from_knx_wrong_crd2(self):
         knxipframe = KNXIPFrame(xknx)
         with self.assertRaises(CouldNotParseKNXIP):
             knxipframe.from_knx(raw)
+
+    def test_connect_response_connection_error(self):
+        """Test parsing and streaming connection response KNX/IP packet with error."""
+        raw = ((0x06, 0x10, 0x02, 0x06, 0x00, 0x08, 0x00, 0x24))
+        xknx = XKNX(loop=self.loop)
+        knxipframe = KNXIPFrame(xknx)
+        knxipframe.from_knx(raw)
+        self.assertTrue(isinstance(knxipframe.body, ConnectResponse))
+        self.assertEqual(knxipframe.body.status_code, ErrorCode.E_NO_MORE_CONNECTIONS)
+        self.assertEqual(knxipframe.body.communication_channel, 0)
+
+        knxipframe2 = KNXIPFrame(xknx)
+        knxipframe2.init(KNXIPServiceType.CONNECT_RESPONSE)
+        knxipframe2.body.status_code = ErrorCode.E_NO_MORE_CONNECTIONS
+        knxipframe2.normalize()
+
+        self.assertEqual(knxipframe2.to_knx(), list(raw))
diff --git a/xknx/knxip/connect_response.py b/xknx/knxip/connect_response.py
index 514103c15..1d96e81d6 100644
--- a/xknx/knxip/connect_response.py
+++ b/xknx/knxip/connect_response.py
@@ -33,8 +33,10 @@ def __init__(self, xknx):
 
     def calculated_length(self):
         """Get length of KNX/IP body."""
-        return 2 + HPAI.LENGTH + \
-            ConnectResponse.CRD_LENGTH
+        if self.status_code == ErrorCode.E_NO_ERROR:
+            return 2 + HPAI.LENGTH + \
+                ConnectResponse.CRD_LENGTH
+        return 2
 
     def from_knx(self, raw):
         """Parse/deserialize from KNX/IP raw data."""
@@ -52,8 +54,9 @@ def crd_from_knx(crd):
         self.status_code = ErrorCode(raw[1])
         pos = 2
 
-        pos += self.control_endpoint.from_knx(raw[pos:])
-        pos += crd_from_knx(raw[pos:])
+        if self.status_code == ErrorCode.E_NO_ERROR:
+            pos += self.control_endpoint.from_knx(raw[pos:])
+            pos += crd_from_knx(raw[pos:])
         return pos
 
     def to_knx(self):
@@ -69,8 +72,11 @@ def crd_to_knx():
         data = []
         data.append(self.communication_channel)
         data.append(self.status_code.value)
-        data.extend(self.control_endpoint.to_knx())
-        data.extend(crd_to_knx())
+
+        if self.status_code == ErrorCode.E_NO_ERROR:
+            data.extend(self.control_endpoint.to_knx())
+            data.extend(crd_to_knx())
+
         return data
 
     def __str__(self):