diff --git a/docker/utils/utils.py b/docker/utils/utils.py
index f36a3afb..4d3980f9 100644
--- a/docker/utils/utils.py
+++ b/docker/utils/utils.py
@@ -103,7 +103,7 @@ def _convert_port_binding(binding):
         result['HostPort'] = binding
 
     if result['HostPort'] is None:
-        result['HostPort'] = ''
+        result['HostPort'] = '0'
     else:
         result['HostPort'] = str(result['HostPort'])
 
diff --git a/tests/unit/api_container_test.py b/tests/unit/api_container_test.py
index b2e5237a..cf1ca4bf 100644
--- a/tests/unit/api_container_test.py
+++ b/tests/unit/api_container_test.py
@@ -596,7 +596,7 @@ class CreateContainerTest(BaseAPIClientTest):
         assert '4444/tcp' in port_bindings
         assert '5555/tcp' in port_bindings
         assert '6666/tcp' in port_bindings
-        assert [{"HostPort": "", "HostIp": ""}] == port_bindings['1111/tcp']
+        assert [{"HostPort": "0", "HostIp": ""}] == port_bindings['1111/tcp']
         assert [
             {"HostPort": "2222", "HostIp": ""}
         ] == port_bindings['2222/tcp']
diff --git a/tests/unit/models_containers_test.py b/tests/unit/models_containers_test.py
index 0e2ae341..d5a03787 100644
--- a/tests/unit/models_containers_test.py
+++ b/tests/unit/models_containers_test.py
@@ -177,7 +177,7 @@ class ContainerCollectionTest(unittest.TestCase):
                 'PidsLimit': 500,
                 'PortBindings': {
                     '1111/tcp': [{'HostIp': '', 'HostPort': '4567'}],
-                    '2222/tcp': [{'HostIp': '', 'HostPort': ''}]
+                    '2222/tcp': [{'HostIp': '', 'HostPort': '0'}]
                 },
                 'Privileged': True,
                 'PublishAllPorts': True,