diff --git a/envisage/plugin_manager.py b/envisage/plugin_manager.py
index 74beb75bb..d7c1e9cf9 100644
--- a/envisage/plugin_manager.py
+++ b/envisage/plugin_manager.py
@@ -12,6 +12,7 @@
 
 from fnmatch import fnmatch
 import logging
+import warnings
 
 from traits.api import Event, HasTraits, Instance, List, observe, provides, Str
 
@@ -82,6 +83,14 @@ def __init__(self, plugins=None, **traits):
         plugins use 'for plugin in plugin_manager'.
 
         """
+        if "include" in traits or "exclude" in traits:
+            warnings.warn(
+                "The 'include' and 'exclude' traits to PluginManager "
+                "are deprecated, and will be removed in a future version "
+                "of Envisage",
+                DeprecationWarning,
+                stacklevel=2,
+            )
 
         super().__init__(**traits)
 
diff --git a/envisage/tests/test_plugin_manager.py b/envisage/tests/test_plugin_manager.py
index e3f2ed280..e3615bb60 100644
--- a/envisage/tests/test_plugin_manager.py
+++ b/envisage/tests/test_plugin_manager.py
@@ -143,14 +143,15 @@ def test_only_include_plugins_whose_ids_are_in_the_include_list(self):
         # plugins Ids.
         include = ["foo", "bar"]
 
-        plugin_manager = PluginManager(
-            include=include,
-            plugins=[
-                SimplePlugin(id="foo"),
-                SimplePlugin(id="bar"),
-                SimplePlugin(id="baz"),
-            ],
-        )
+        with self.assertWarns(DeprecationWarning):
+            plugin_manager = PluginManager(
+                include=include,
+                plugins=[
+                    SimplePlugin(id="foo"),
+                    SimplePlugin(id="bar"),
+                    SimplePlugin(id="baz"),
+                ],
+            )
 
         # The Ids of the plugins that we expect the plugin manager to find.
         expected = ["foo", "bar"]
@@ -167,14 +168,15 @@ def test_only_include_plugins_matching_a_wildcard_in_the_include_list(
         # plugins Ids.
         include = ["b*"]
 
-        plugin_manager = PluginManager(
-            include=include,
-            plugins=[
-                SimplePlugin(id="foo"),
-                SimplePlugin(id="bar"),
-                SimplePlugin(id="baz"),
-            ],
-        )
+        with self.assertWarns(DeprecationWarning):
+            plugin_manager = PluginManager(
+                include=include,
+                plugins=[
+                    SimplePlugin(id="foo"),
+                    SimplePlugin(id="bar"),
+                    SimplePlugin(id="baz"),
+                ],
+            )
 
         # The Ids of the plugins that we expect the plugin manager to find.
         expected = ["bar", "baz"]
@@ -189,14 +191,15 @@ def test_ignore_plugins_whose_ids_are_in_the_exclude_list(self):
         # plugins Ids.
         exclude = ["foo", "baz"]
 
-        plugin_manager = PluginManager(
-            exclude=exclude,
-            plugins=[
-                SimplePlugin(id="foo"),
-                SimplePlugin(id="bar"),
-                SimplePlugin(id="baz"),
-            ],
-        )
+        with self.assertWarns(DeprecationWarning):
+            plugin_manager = PluginManager(
+                exclude=exclude,
+                plugins=[
+                    SimplePlugin(id="foo"),
+                    SimplePlugin(id="bar"),
+                    SimplePlugin(id="baz"),
+                ],
+            )
 
         # The Ids of the plugins that we expect the plugin manager to find.
         expected = ["bar"]
@@ -211,14 +214,15 @@ def test_ignore_plugins_matching_a_wildcard_in_the_exclude_list(self):
         # plugins Ids.
         exclude = ["b*"]
 
-        plugin_manager = PluginManager(
-            exclude=exclude,
-            plugins=[
-                SimplePlugin(id="foo"),
-                SimplePlugin(id="bar"),
-                SimplePlugin(id="baz"),
-            ],
-        )
+        with self.assertWarns(DeprecationWarning):
+            plugin_manager = PluginManager(
+                exclude=exclude,
+                plugins=[
+                    SimplePlugin(id="foo"),
+                    SimplePlugin(id="bar"),
+                    SimplePlugin(id="baz"),
+                ],
+            )
 
         # The Ids of the plugins that we expect the plugin manager to find.
         expected = ["foo"]