diff --git a/java/test/org/openqa/selenium/grid/data/DefaultSlotMatcherTest.java b/java/test/org/openqa/selenium/grid/data/DefaultSlotMatcherTest.java
index 80410be005e0f..2c531ef18f190 100644
--- a/java/test/org/openqa/selenium/grid/data/DefaultSlotMatcherTest.java
+++ b/java/test/org/openqa/selenium/grid/data/DefaultSlotMatcherTest.java
@@ -67,6 +67,31 @@ void fullMatch() {
     assertThat(slotMatcher.matches(stereotype, capabilities)).isTrue();
   }
 
+  @Test
+  void fullMatchExtensionCaps() {
+    Capabilities stereotype =
+        new ImmutableCapabilities(
+            CapabilityType.BROWSER_NAME,
+            "firefox",
+            CapabilityType.PLATFORM_NAME,
+            Platform.WINDOWS,
+            "se:downloadsEnabled",
+            true,
+            "moz:debuggerAddress",
+            "127.0.0.1:34959");
+    Capabilities capabilities =
+        new ImmutableCapabilities(
+            CapabilityType.BROWSER_NAME,
+            "firefox",
+            CapabilityType.PLATFORM_NAME,
+            Platform.WINDOWS,
+            "se:downloadsEnabled",
+            true,
+            "moz:debuggerAddress",
+            true);
+    assertThat(slotMatcher.matches(stereotype, capabilities)).isTrue();
+  }
+
   @Test
   void fullMatchWithTestMetadata() {
     Capabilities stereotype =