diff --git a/features/manager/input_events.feature b/features/manager/input_events.feature
new file mode 100644
index 0000000..f2868a1
--- /dev/null
+++ b/features/manager/input_events.feature
@@ -0,0 +1,8 @@
+Feature: input events selection
+
+  Scenario: selects the appropriate input event mask for a window manager
+    Given uhwm is running
+    Then the input event mask must include StructureNotifyMask
+    And the input event mask must include SubstructureNotifyMask
+    And the input event mask must include SubstructureRedirectMask
+    And the input event mask must include PropertyChangeMask
diff --git a/features/steps/x_steps.rb b/features/steps/x_steps.rb
index 5a40dc1..735e65a 100644
--- a/features/steps/x_steps.rb
+++ b/features/steps/x_steps.rb
@@ -18,3 +18,7 @@ end
 Then /^the window must be focused$/ do
   expect(x_focused_window_id).to eq x_window_id
 end
+
+Then /^the input event mask must include (.+)$/ do |mask|
+  expect(x_input_event_masks).to include mask
+end
diff --git a/lib/uh/wm/testing/acceptance_helpers.rb b/lib/uh/wm/testing/acceptance_helpers.rb
index 829fdd0..7e63216 100644
--- a/lib/uh/wm/testing/acceptance_helpers.rb
+++ b/lib/uh/wm/testing/acceptance_helpers.rb
@@ -64,6 +64,10 @@ module Uh
           Integer(`xdpyinfo`[/^focus:\s+window\s+(0x\h+)/, 1])
         end
 
+        def x_input_event_masks
+          `xdpyinfo`[/current input event mask:\s+0x\h+([\w\s]+):/, 1].split(/\s+/).grep /Mask\z/
+        end
+
         def x_key key
           fail "cannot simulate X key `#{key}'" unless system "xdotool key #{key}"
         end