--- a/testing/web-platform/mozilla/meta/MANIFEST.json
+++ b/testing/web-platform/mozilla/meta/MANIFEST.json
@@ -968,16 +968,24 @@
     ]
    ],
    "wasm/unwind.wast.js.html": [
     [
      "/_mozilla/wasm/unwind.wast.js.html",
      {}
     ]
    ]
+  },
+  "wdspec": {
+   "webdriver/full_document_screenshot.py": [
+    [
+     "/_mozilla/webdriver/full_document_screenshot.py",
+     {}
+    ]
+   ]
   }
  },
  "paths": {
   "./placeholder": [
    "74e16eb87ecdfeb2dfc28f36e0c73a584abdf9c2",
    "support"
   ],
   "dom/classList.html": [
@@ -1670,13 +1678,17 @@
   ],
   "wasm/unreached-invalid.wast.js.html": [
    "a7189041a6ab02747c4cd944ec2b2b2a68d60708",
    "testharness"
   ],
   "wasm/unwind.wast.js.html": [
    "de651ab0442bd191626009d1b0aa3cf03130117f",
    "testharness"
+  ],
+  "webdriver/full_document_screenshot.py": [
+   "b3747a5c30543916d206921808c253c785ad9105",
+   "wdspec"
   ]
  },
  "url_base": "/_mozilla/",
  "version": 4
 }

new file mode 100644
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/webdriver/full_document_screenshot.py
@@ -0,0 +1,5 @@
+def take_full_document_screenshot(session):
+    response = session.transport.send("GET", "session/{session_id}/moz/screenshot/full"
+                                      .format(session_id=session.session_id))
+
+    assert response.status == 200, str(response.error)
\ No newline at end of file