diff --git a/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.out b/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.out
new file mode 100644
index 000000000..98132eca3
--- /dev/null
+++ b/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.out
@@ -0,0 +1,23 @@
+[
+  "@generated",
+  {
+    "key": {
+      "declaration": {
+        "method": {
+          "key": {
+            "name": { "key": "bar" },
+            "container": {
+              "class_": {
+                "key": {
+                  "name": { "key": { "name": { "key": "SourceClass" } } }
+                }
+              }
+            }
+          }
+        }
+      },
+      "file": { "key": "www/SourceClass.php" },
+      "span": { "start": 408, "length": 3 }
+    }
+  }
+]
\ No newline at end of file
diff --git a/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.perf b/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.perf
new file mode 100644
index 000000000..602582a92
--- /dev/null
+++ b/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.perf
@@ -0,0 +1,8 @@
+{
+  "@generated": null,
+  "hack.ClassDeclaration.6": 1,
+  "hack.DeclarationLocation.6": 1,
+  "hack.MethodDeclaration.6": 1,
+  "hack.Name.6": 6,
+  "hack.QName.6": 3
+}
\ No newline at end of file
diff --git a/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.query b/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.query
new file mode 100644
index 000000000..0e0d9fe64
--- /dev/null
+++ b/glean/lang/codemarkup/tests/hack/cases/xrefs/declarationnamespace.query
@@ -0,0 +1,33 @@
+query: |
+  hack.DeclarationLocation
+    {
+      declaration =  {
+          method = hack.MethodDeclaration.6 {
+            name="bar",
+            container = {
+              class_ = hack.ClassDeclaration.6 {
+                name = hack.QName.6 {
+                  name = "SourceClass",
+                  namespace_ = {nothing={}}
+                }
+              }
+            } | {
+              interface_ = hack.InterfaceDeclaration.6 {
+                name=hack.QName.6 {
+                  name = "SourceClass",
+                  namespace_={nothing={}}
+                }
+              }
+            } | {
+              trait = hack.TraitDeclaration.6 {
+                name = hack.QName.6 {
+                  name = "SourceClass",
+                  namespace_ = {nothing={}}
+                }
+              }
+            }
+          }
+        }
+  }
+perf: true
+transform: [gensort, []]