diff --git a/pyblish/__init__.py b/pyblish/__init__.py
index dba65fb5..51546b9f 100644
--- a/pyblish/__init__.py
+++ b/pyblish/__init__.py
@@ -14,4 +14,4 @@
 _registered_plugins = dict()
 _registered_services = dict()
 _registered_test = None
-_registered_hosts = set()
+_registered_hosts = list()
diff --git a/pyblish/plugin.py b/pyblish/plugin.py
index daa3c8fc..6db3e2b9 100644
--- a/pyblish/plugin.py
+++ b/pyblish/plugin.py
@@ -875,7 +875,8 @@ def register_host(host):
 
     """
 
-    pyblish._registered_hosts.add(host)
+    if not host in pyblish._registered_hosts:
+        pyblish._registered_hosts.append(host)
 
 
 def deregister_host(host, quiet=False):
@@ -897,7 +898,7 @@ def deregister_host(host, quiet=False):
 
 
 def deregister_all_hosts():
-    pyblish._registered_hosts.clear()
+    pyblish._registered_hosts[:] = []
 
 
 def registered_hosts():
diff --git a/tests/lib.py b/tests/lib.py
index 8987049a..acf14321 100644
--- a/tests/lib.py
+++ b/tests/lib.py
@@ -28,6 +28,7 @@ def setup_empty():
     """Disable all plug-ins"""
     setup()
     pyblish.plugin.deregister_all_paths()
+    pyblish.plugin.deregister_all_hosts()
 
 
 def teardown():
@@ -42,4 +43,6 @@ def teardown():
 
     os.environ["PYBLISHPLUGINPATH"] = ENVIRONMENT
     pyblish.api.deregister_all_plugins()
+    pyblish.api.deregister_all_hosts()
     pyblish.api.deregister_test()
+    pyblish.api.__init__()
diff --git a/tests/test_plugin.py b/tests/test_plugin.py
index dee9b150..23430bda 100644
--- a/tests/test_plugin.py
+++ b/tests/test_plugin.py
@@ -221,3 +221,19 @@ def process(self, context):
     records = results["records"]
     hello_world = records[0]
     assert_equals(hello_world.msg, "Hello world")
+
+
+@with_setup(lib.setup_empty, lib.teardown)
+def test_current_host():
+    """pyblish.api.current_host works"""
+    pyblish.plugin.register_host("myhost")
+    assert_equals(pyblish.plugin.current_host(), "myhost")
+
+
+@with_setup(lib.setup_empty, lib.teardown)
+def test_register_host():
+    """Registering and deregistering hosts works fine"""
+    pyblish.plugin.register_host("myhost")
+    assert "myhost" in pyblish.plugin.registered_hosts()
+    pyblish.plugin.deregister_host("myhost")
+    assert "myhost" not in pyblish.plugin.registered_hosts()