diff --git a/.travis.yml b/.travis.yml
index 6b48142f72..86f2a1bfde 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,14 +1,19 @@
 sudo: false
 language: python
+cache: pip
 python:
-  - "3.5"
-env:
-    - TOX_ENV=py27
-    - TOX_ENV=py33
-    - TOX_ENV=py34
-    - TOX_ENV=py35
-    - TOX_ENV=flake8
+  - 2.7
+  - 3.3
+  - 3.4
+  - 3.5
+  - 3.6
+  - pypy
+  - pypy3
+matrix:
+  allow_failures:
+    - python: pypy
+    - python: pypy3
 install:
-    - pip install tox
+    - travis_retry pip install tox-travis
 script:
-    - tox -e $TOX_ENV
+    - tox
diff --git a/Dockerfile-pypy b/Dockerfile-pypy
new file mode 100644
index 0000000000..7c26e8a80e
--- /dev/null
+++ b/Dockerfile-pypy
@@ -0,0 +1,14 @@
+FROM pypy:2
+MAINTAINER Joffrey F <joffrey@docker.com>
+
+RUN mkdir /home/docker-py
+WORKDIR /home/docker-py
+
+ADD requirements.txt /home/docker-py/requirements.txt
+RUN pip install -r requirements.txt
+
+ADD test-requirements.txt /home/docker-py/test-requirements.txt
+RUN pip install -r test-requirements.txt
+
+ADD . /home/docker-py
+RUN pip install .
diff --git a/Dockerfile-pypy3 b/Dockerfile-pypy3
new file mode 100644
index 0000000000..8826f7e4cb
--- /dev/null
+++ b/Dockerfile-pypy3
@@ -0,0 +1,14 @@
+FROM pypy:3
+MAINTAINER Joffrey F <joffrey@docker.com>
+
+RUN mkdir /home/docker-py
+WORKDIR /home/docker-py
+
+ADD requirements.txt /home/docker-py/requirements.txt
+RUN pip install -r requirements.txt
+
+ADD test-requirements.txt /home/docker-py/test-requirements.txt
+RUN pip install -r test-requirements.txt
+
+ADD . /home/docker-py
+RUN pip install .
diff --git a/Makefile b/Makefile
index e8fa711aba..c8f25476e5 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,14 @@ build:
 build-py3:
 	docker build -t docker-sdk-python3 -f Dockerfile-py3 .
 
+.PHONY: build-pypy
+build-pypy:
+	docker build -t docker-sdk-pypy -f Dockerfile-pypy .
+
+.PHONY: build-pypy3
+build-pypy3:
+	docker build -t docker-sdk-pypy3 -f Dockerfile-pypy3 .
+
 .PHONY: build-docs
 build-docs:
 	docker build -t docker-sdk-python-docs -f Dockerfile-docs .
@@ -23,7 +31,7 @@ build-dind-certs:
 	docker build -t dpy-dind-certs -f tests/Dockerfile-dind-certs .
 
 .PHONY: test
-test: flake8 unit-test unit-test-py3 integration-dind integration-dind-ssl
+test: flake8 unit-test unit-test-py3 unit-test-pypy unit-test-pypy3 integration-dind integration-dind-ssl
 
 .PHONY: unit-test
 unit-test: build
@@ -33,6 +41,14 @@ unit-test: build
 unit-test-py3: build-py3
 	docker run --rm docker-sdk-python3 py.test tests/unit
 
+.PHONY: unit-test-pypy
+unit-test-pypy: build-pypy
+	docker run docker-sdk-pypy py.test tests/unit
+
+.PHONY: unit-test-pypy3
+unit-test-pypy3: build-pypy3
+	docker run docker-sdk-pypy3 py.test tests/unit
+
 .PHONY: integration-test
 integration-test: build
 	docker run --rm -v /var/run/docker.sock:/var/run/docker.sock docker-sdk-python py.test tests/integration/${file}
@@ -41,6 +57,14 @@ integration-test: build
 integration-test-py3: build-py3
 	docker run --rm -v /var/run/docker.sock:/var/run/docker.sock docker-sdk-python3 py.test tests/integration/${file}
 
+.PHONY: integration-test-pypy
+integration-test-pypy: build-pypy
+	docker run --rm -v /var/run/docker.sock:/var/run/docker.sock docker-sdk-pypy py.test tests/integration/${file}
+
+.PHONY: integration-test-pypy3
+integration-test-pypy3: build-pypy3
+	docker run --rm -v /var/run/docker.sock:/var/run/docker.sock docker-sdk-pypy3 py.test tests/integration/${file}
+
 .PHONY: integration-dind
 integration-dind: build build-py3
 	docker rm -vf dpy-dind || :
diff --git a/README.md b/README.md
index 38963b325c..55fec226d1 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@
 [![Build Status](https://travis-ci.org/docker/docker-py.svg?branch=master)](https://travis-ci.org/docker/docker-py)
 
 A Python library for the Docker Engine API. It lets you do anything the `docker` command does, but from within Python apps – run containers, manage containers, manage Swarms, etc.
+It supports Python 2 and Python 3 implemented by CPython and PyPy.
 
 ## Installation
 
diff --git a/docker/utils/ports.py b/docker/utils/ports.py
index e2aeb8cc52..3708958d4e 100644
--- a/docker/utils/ports.py
+++ b/docker/utils/ports.py
@@ -67,6 +67,8 @@ def split_port(port):
 
     if len(parts) == 1:
         internal_port, = parts
+        if not internal_port:
+            _raise_invalid_port(port)
         return to_port_range(internal_port), None
     if len(parts) == 2:
         external_port, internal_port = parts
diff --git a/setup.py b/setup.py
index 9fc4ad66e9..92f211f552 100644
--- a/setup.py
+++ b/setup.py
@@ -77,6 +77,9 @@
         'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: Implementation :: CPython',
+        'Programming Language :: Python :: Implementation :: PyPy',
         'Topic :: Utilities',
         'License :: OSI Approved :: Apache Software License',
     ],
diff --git a/tests/integration/api_client_test.py b/tests/integration/api_client_test.py
index 1fef783b4d..cc641582c0 100644
--- a/tests/integration/api_client_test.py
+++ b/tests/integration/api_client_test.py
@@ -8,7 +8,7 @@
 import docker
 from docker.utils import kwargs_from_env
 
-from .base import BaseAPIIntegrationTest, BUSYBOX
+from .base import BaseAPIIntegrationTest
 
 
 class InformationTest(BaseAPIIntegrationTest):
@@ -25,48 +25,6 @@ def test_info(self):
         self.assertIn('Debug', res)
 
 
-class LinkTest(BaseAPIIntegrationTest):
-    def test_remove_link(self):
-        # Create containers
-        container1 = self.client.create_container(
-            BUSYBOX, 'cat', detach=True, stdin_open=True
-        )
-        container1_id = container1['Id']
-        self.tmp_containers.append(container1_id)
-        self.client.start(container1_id)
-
-        # Create Link
-        # we don't want the first /
-        link_path = self.client.inspect_container(container1_id)['Name'][1:]
-        link_alias = 'mylink'
-
-        container2 = self.client.create_container(
-            BUSYBOX, 'cat', host_config=self.client.create_host_config(
-                links={link_path: link_alias}
-            )
-        )
-        container2_id = container2['Id']
-        self.tmp_containers.append(container2_id)
-        self.client.start(container2_id)
-
-        # Remove link
-        linked_name = self.client.inspect_container(container2_id)['Name'][1:]
-        link_name = '%s/%s' % (linked_name, link_alias)
-        self.client.remove_container(link_name, link=True)
-
-        # Link is gone
-        containers = self.client.containers(all=True)
-        retrieved = [x for x in containers if link_name in x['Names']]
-        self.assertEqual(len(retrieved), 0)
-
-        # Containers are still there
-        retrieved = [
-            x for x in containers if x['Id'].startswith(container1_id) or
-            x['Id'].startswith(container2_id)
-        ]
-        self.assertEqual(len(retrieved), 2)
-
-
 class LoadConfigTest(BaseAPIIntegrationTest):
     def test_load_legacy_config(self):
         folder = tempfile.mkdtemp()
diff --git a/tests/integration/api_container_test.py b/tests/integration/api_container_test.py
index f539697e9e..9514261512 100644
--- a/tests/integration/api_container_test.py
+++ b/tests/integration/api_container_test.py
@@ -1253,3 +1253,45 @@ def test_container_cpuset(self):
         self.client.start(container)
         inspect_data = self.client.inspect_container(container)
         self.assertEqual(inspect_data['HostConfig']['CpusetCpus'], cpuset_cpus)
+
+
+class LinkTest(BaseAPIIntegrationTest):
+    def test_remove_link(self):
+        # Create containers
+        container1 = self.client.create_container(
+            BUSYBOX, 'cat', detach=True, stdin_open=True
+        )
+        container1_id = container1['Id']
+        self.tmp_containers.append(container1_id)
+        self.client.start(container1_id)
+
+        # Create Link
+        # we don't want the first /
+        link_path = self.client.inspect_container(container1_id)['Name'][1:]
+        link_alias = 'mylink'
+
+        container2 = self.client.create_container(
+            BUSYBOX, 'cat', host_config=self.client.create_host_config(
+                links={link_path: link_alias}
+            )
+        )
+        container2_id = container2['Id']
+        self.tmp_containers.append(container2_id)
+        self.client.start(container2_id)
+
+        # Remove link
+        linked_name = self.client.inspect_container(container2_id)['Name'][1:]
+        link_name = '%s/%s' % (linked_name, link_alias)
+        self.client.remove_container(link_name, link=True)
+
+        # Link is gone
+        containers = self.client.containers(all=True)
+        retrieved = [x for x in containers if link_name in x['Names']]
+        self.assertEqual(len(retrieved), 0)
+
+        # Containers are still there
+        retrieved = [
+            x for x in containers if x['Id'].startswith(container1_id) or
+            x['Id'].startswith(container2_id)
+        ]
+        self.assertEqual(len(retrieved), 2)
diff --git a/tests/unit/utils_test.py b/tests/unit/utils_test.py
index ed84b3a1fd..4c3c3664a2 100644
--- a/tests/unit/utils_test.py
+++ b/tests/unit/utils_test.py
@@ -578,6 +578,9 @@ def test_with_no_container_port(self):
         self.assertRaises(ValueError,
                           lambda: split_port("localhost:80:"))
 
+    def test_split_port_empty_string(self):
+        self.assertRaises(ValueError, lambda: split_port(""))
+
     def test_build_port_bindings_with_one_port(self):
         port_bindings = build_port_bindings(["127.0.0.1:1000:1000"])
         self.assertEqual(port_bindings["1000"], [("127.0.0.1", "1000")])
diff --git a/tox.ini b/tox.ini
index 1a41c6edac..a1eba5288f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,9 +1,9 @@
 [tox]
-envlist = py27, py33, py34, py35, flake8
-skipsdist=True
+envlist = py27, py33, py34, py35, py36, pypy, pypy3, flake8
+skipsdist = True
 
 [testenv]
-usedevelop=True
+usedevelop = True
 commands =
     py.test --cov=docker {posargs:tests/unit}
 deps =