diff --git a/tests/draft-next/ref.json b/tests/draft-next/ref.json
index 421b5f85..f2b5fc00 100644
--- a/tests/draft-next/ref.json
+++ b/tests/draft-next/ref.json
@@ -642,5 +642,193 @@
                 "valid": false
             }
         ]
+    },
+    {
+        "description": "simple URN base URI with $ref via the URN",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed",
+            "minimum": 30,
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed"}
+            }
+        },
+        "tests": [
+            {
+                "description": "valid under the URN IDed schema",
+                "data": {"foo": 37},
+                "valid": true
+            },
+            {
+                "description": "invalid under the URN IDed schema",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "simple URN base URI with JSON pointer",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with NSS",
+        "schema": {
+            "$comment": "RFC 8141 §2.2",
+            "$id": "urn:example:1/406/47452/2",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with r-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.1",
+            "$id": "urn:example:foo-bar-baz-qux?+CCResolve:cc=uk",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with q-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.2",
+            "$id": "urn:example:weather?=op=map&lat=39.56&lon=-104.85&datetime=1969-07-21T02:56:15Z",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with f-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.3, but we don't allow fragments",
+            "$ref": "https://json-schema.org/draft/next/schema"
+        },
+        "tests": [
+            {
+                "description": "is invalid",
+                "data": {"$id": "urn:example:foo-bar-baz-qux#somepart"},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and JSON pointer ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and anchor ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed#something"}
+            },
+            "$defs": {
+                "bar": {
+                    "$anchor": "something",
+                    "type": "string"
+                }
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
     }
 ]
diff --git a/tests/draft2019-09/ref.json b/tests/draft2019-09/ref.json
index 55a447c4..32e3c664 100644
--- a/tests/draft2019-09/ref.json
+++ b/tests/draft2019-09/ref.json
@@ -642,5 +642,193 @@
                 "valid": false
             }
         ]
+    },
+    {
+        "description": "simple URN base URI with $ref via the URN",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed",
+            "minimum": 30,
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed"}
+            }
+        },
+        "tests": [
+            {
+                "description": "valid under the URN IDed schema",
+                "data": {"foo": 37},
+                "valid": true
+            },
+            {
+                "description": "invalid under the URN IDed schema",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "simple URN base URI with JSON pointer",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-00ff-ff00-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with NSS",
+        "schema": {
+            "$comment": "RFC 8141 §2.2",
+            "$id": "urn:example:1/406/47452/2",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with r-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.1",
+            "$id": "urn:example:foo-bar-baz-qux?+CCResolve:cc=uk",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with q-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.2",
+            "$id": "urn:example:weather?=op=map&lat=39.56&lon=-104.85&datetime=1969-07-21T02:56:15Z",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with f-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.3, but we don't allow fragments",
+            "$ref": "https://json-schema.org/draft/2019-09/schema"
+        },
+        "tests": [
+            {
+                "description": "is invalid",
+                "data": {"$id": "urn:example:foo-bar-baz-qux#somepart"},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and JSON pointer ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and anchor ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-ff00-00ff-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ff00-00ff-4321feebdaed#something"}
+            },
+            "$defs": {
+                "bar": {
+                    "$anchor": "something",
+                    "type": "string"
+                }
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
     }
 ]
diff --git a/tests/draft2020-12/ref.json b/tests/draft2020-12/ref.json
index 122ff750..bc8ac447 100644
--- a/tests/draft2020-12/ref.json
+++ b/tests/draft2020-12/ref.json
@@ -642,5 +642,193 @@
                 "valid": false
             }
         ]
+    },
+    {
+        "description": "simple URN base URI with $ref via the URN",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed",
+            "minimum": 30,
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed"}
+            }
+        },
+        "tests": [
+            {
+                "description": "valid under the URN IDed schema",
+                "data": {"foo": 37},
+                "valid": true
+            },
+            {
+                "description": "invalid under the URN IDed schema",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "simple URN base URI with JSON pointer",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-00ff-ff00-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with NSS",
+        "schema": {
+            "$comment": "RFC 8141 §2.2",
+            "$id": "urn:example:1/406/47452/2",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with r-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.1",
+            "$id": "urn:example:foo-bar-baz-qux?+CCResolve:cc=uk",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with q-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.2",
+            "$id": "urn:example:weather?=op=map&lat=39.56&lon=-104.85&datetime=1969-07-21T02:56:15Z",
+            "properties": {
+                "foo": {"$ref": "#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with f-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.3, but we don't allow fragments",
+            "$ref": "https://json-schema.org/draft/2020-12/schema"
+        },
+        "tests": [
+            {
+                "description": "is invalid",
+                "data": {"$id": "urn:example:foo-bar-baz-qux#somepart"},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and JSON pointer ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and anchor ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-ff00-00ff-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ff00-00ff-4321feebdaed#something"}
+            },
+            "$defs": {
+                "bar": {
+                    "$anchor": "something",
+                    "type": "string"
+                }
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
     }
 ]
diff --git a/tests/draft6/ref.json b/tests/draft6/ref.json
index ce5caf67..3e72a596 100644
--- a/tests/draft6/ref.json
+++ b/tests/draft6/ref.json
@@ -608,5 +608,179 @@
                 "valid": true
             }
         ]
+    },
+    {
+        "description": "simple URN base URI with $ref via the URN",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed",
+            "minimum": 30,
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed"}
+            }
+        },
+        "tests": [
+            {
+                "description": "valid under the URN IDed schema",
+                "data": {"foo": 37},
+                "valid": true
+            },
+            {
+                "description": "invalid under the URN IDed schema",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "simple URN base URI with JSON pointer",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-00ff-ff00-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "#/definitions/bar"}
+            },
+            "definitions": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with NSS",
+        "schema": {
+            "$comment": "RFC 8141 §2.2",
+            "$id": "urn:example:1/406/47452/2",
+            "properties": {
+                "foo": {"$ref": "#/definitions/bar"}
+            },
+            "definitions": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with r-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.1",
+            "$id": "urn:example:foo-bar-baz-qux?+CCResolve:cc=uk",
+            "properties": {
+                "foo": {"$ref": "#/definitions/bar"}
+            },
+            "definitions": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with q-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.2",
+            "$id": "urn:example:weather?=op=map&lat=39.56&lon=-104.85&datetime=1969-07-21T02:56:15Z",
+            "properties": {
+                "foo": {"$ref": "#/definitions/bar"}
+            },
+            "definitions": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and JSON pointer ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and anchor ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-ff00-00ff-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ff00-00ff-4321feebdaed#something"}
+            },
+            "$defs": {
+                "bar": {
+                    "$id": "#something",
+                    "type": "string"
+                }
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
     }
 ]
diff --git a/tests/draft7/ref.json b/tests/draft7/ref.json
index 764d6379..52e51683 100644
--- a/tests/draft7/ref.json
+++ b/tests/draft7/ref.json
@@ -644,5 +644,179 @@
                 "valid": false
             }
         ]
+    },
+    {
+        "description": "simple URN base URI with $ref via the URN",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed",
+            "minimum": 30,
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ffff-ffff-4321feebdaed"}
+            }
+        },
+        "tests": [
+            {
+                "description": "valid under the URN IDed schema",
+                "data": {"foo": 37},
+                "valid": true
+            },
+            {
+                "description": "invalid under the URN IDed schema",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "simple URN base URI with JSON pointer",
+        "schema": {
+            "$comment": "URIs do not have to have HTTP(s) schemes",
+            "$id": "urn:uuid:deadbeef-1234-00ff-ff00-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "#/definitions/bar"}
+            },
+            "definitions": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with NSS",
+        "schema": {
+            "$comment": "RFC 8141 §2.2",
+            "$id": "urn:example:1/406/47452/2",
+            "properties": {
+                "foo": {"$ref": "#/definitions/bar"}
+            },
+            "definitions": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with r-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.1",
+            "$id": "urn:example:foo-bar-baz-qux?+CCResolve:cc=uk",
+            "properties": {
+                "foo": {"$ref": "#/definitions/bar"}
+            },
+            "definitions": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with q-component",
+        "schema": {
+            "$comment": "RFC 8141 §2.3.2",
+            "$id": "urn:example:weather?=op=map&lat=39.56&lon=-104.85&datetime=1969-07-21T02:56:15Z",
+            "properties": {
+                "foo": {"$ref": "#/definitions/bar"}
+            },
+            "definitions": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and JSON pointer ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-0000-0000-4321feebdaed#/$defs/bar"}
+            },
+            "$defs": {
+                "bar": {"type": "string"}
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
+    },
+    {
+        "description": "URN base URI with URN and anchor ref",
+        "schema": {
+            "$id": "urn:uuid:deadbeef-1234-ff00-00ff-4321feebdaed",
+            "properties": {
+                "foo": {"$ref": "urn:uuid:deadbeef-1234-ff00-00ff-4321feebdaed#something"}
+            },
+            "$defs": {
+                "bar": {
+                    "$id": "#something",
+                    "type": "string"
+                }
+            }
+        },
+        "tests": [
+            {
+                "description": "a string is valid",
+                "data": {"foo": "bar"},
+                "valid": true
+            },
+            {
+                "description": "a non-string is invalid",
+                "data": {"foo": 12},
+                "valid": false
+            }
+        ]
     }
 ]