diff --git a/test/baselines/generated-reference/namespaces.html b/test/baselines/generated-reference/namespaces.html
index ca1fbf1d..cdd67cb2 100644
--- a/test/baselines/generated-reference/namespaces.html
+++ b/test/baselines/generated-reference/namespaces.html
@@ -44,6 +44,8 @@ <h1><span class="secnum">1.1</span> Clause 1.1</h1>
 </emu-production>
 </emu-grammar>
 
+    <!-- FIXME: Shouldn't this be allowed by the preceding `namespace=clause`? -->
+    <!-- EXPECT_WARNING { "ruleId": "duplicate-definition", "message": "duplicate definition \"SomeAlg\"" } -->
     <emu-clause id="c111" aoid="SomeAlg">
       <h1><span class="secnum">1.1.1</span> SomeAlg</h1>
     </emu-clause>
@@ -63,10 +65,14 @@ <h1><span class="secnum">A</span> Annex</h1>
     </emu-rhs>
 </emu-production>
 </emu-grammar>
+  <!-- FIXME: Shouldn't this be allowed by the preceding `namespace=annex`? -->
+  <!-- EXPECT_WARNING { "ruleId": "duplicate-definition", "message": "duplicate definition \"SomeAlg\"" } -->
   <emu-annex id="annex11" aoid="SomeAlg">
     <h1><span class="secnum">A.1</span> SomeAlg</h1>
   </emu-annex>
 
+  <!-- FIXME: Shouldn't this be allowed by `namespace=annex2`? -->
+  <!-- EXPECT_WARNING { "ruleId": "duplicate-definition", "message": "duplicate definition \"SomeAlg\"" } -->
   <emu-annex id="annex12" aoid="SomeAlg" namespace="annex2">
     <h1><span class="secnum">A.2</span> Annex 1.2</h1>
     <p><emu-xref aoid="SomeAlg" id="_ref_3"><a href="#i1">SomeAlg</a></emu-xref> should link to #annex12. <emu-nt id="_ref_12"><a href="#prod-annex-Foo">Foo</a></emu-nt> should link to the production in #annex1.</p>
@@ -78,6 +84,7 @@ <h1><span class="secnum">A.2</span> Annex 1.2</h1>
 
 <emu-annex id="annex2" namespace="annex">
   <h1><span class="secnum">B</span> Annex 2</h1>
+  <!-- EXPECT_WARNING { "ruleId": "duplicate-definition", "message": "duplicate definition \"SomeAlg\"" } -->
   <emu-annex id="annex21" aoid="SomeAlg">
     <h1><span class="secnum">B.1</span> SomeAlg</h1>
   </emu-annex>
diff --git a/test/baselines/sources/namespaces.html b/test/baselines/sources/namespaces.html
index 62342d10..3b5d37e9 100644
--- a/test/baselines/sources/namespaces.html
+++ b/test/baselines/sources/namespaces.html
@@ -27,6 +27,8 @@ <h1>Clause 1.1</h1>
         `bar` MainProd `baz`
     </emu-grammar>
 
+    <!-- FIXME: Shouldn't this be allowed by the preceding `namespace=clause`? -->
+    <!-- EXPECT_WARNING { "ruleId": "duplicate-definition", "message": "duplicate definition \"SomeAlg\"" } -->
     <emu-clause id=c111 aoid=SomeAlg>
       <h1>SomeAlg</h1>
     </emu-clause>
@@ -42,10 +44,14 @@ <h1>Annex</h1>
     Foo ::
       `bar` MainProd `baz`
   </emu-grammar>
+  <!-- FIXME: Shouldn't this be allowed by the preceding `namespace=annex`? -->
+  <!-- EXPECT_WARNING { "ruleId": "duplicate-definition", "message": "duplicate definition \"SomeAlg\"" } -->
   <emu-annex id=annex11 aoid=SomeAlg>
     <h1>SomeAlg</h1>
   </emu-annex>
 
+  <!-- FIXME: Shouldn't this be allowed by `namespace=annex2`? -->
+  <!-- EXPECT_WARNING { "ruleId": "duplicate-definition", "message": "duplicate definition \"SomeAlg\"" } -->
   <emu-annex id=annex12 aoid=SomeAlg namespace=annex2>
     <h1>Annex 1.2</h1>
     <p>SomeAlg should link to #annex12. |Foo| should link to the production in #annex1.</p>
@@ -59,6 +65,7 @@ <h1>Annex 1.2</h1>
 
 <emu-annex id=annex2 namespace=annex>
   <h1>Annex 2</h1>
+  <!-- EXPECT_WARNING { "ruleId": "duplicate-definition", "message": "duplicate definition \"SomeAlg\"" } -->
   <emu-annex id=annex21 aoid=SomeAlg>
     <h1>SomeAlg</h1>
   </emu-annex>