diff --git a/src/__tests__/__fixtures__/document-with-external-refs.json b/src/__tests__/__fixtures__/document-with-external-refs.json
new file mode 100644
index 000000000..c91588f1e
--- /dev/null
+++ b/src/__tests__/__fixtures__/document-with-external-refs.json
@@ -0,0 +1,8 @@
+{
+  "todo": {
+    "$ref": "./models/todo-full.v1.json"
+  },
+  "empty": {
+    "$ref": ""
+  }
+}
diff --git a/src/__tests__/__fixtures__/document-with-external-refs.oas2.json b/src/__tests__/__fixtures__/document-with-external-refs.oas2.json
deleted file mode 100644
index a7ccd7298..000000000
--- a/src/__tests__/__fixtures__/document-with-external-refs.oas2.json
+++ /dev/null
@@ -1,37 +0,0 @@
-{
-  "swagger": "2.0",
-  "info": {
-    "title": "To-dos",
-    "version": "1.0",
-    "description": "This OpenAPI v2 (Swagger) file represents a real API that lives at http://todos.stoplight.io.\n\nIt exposes functionality to manage to-do lists."
-  },
-  "host": "todos.stoplight.io",
-  "schemes": ["http"],
-  "paths": {
-    "/todos/{todoId}": {
-      "get": {
-        "operationId": "GET_todo",
-        "summary": "Get Todo",
-        "tags": ["Todos"],
-        "responses": {
-          "200": {
-            "description": "",
-            "schema": {
-              "$ref": "./models/todo-full.v1.json"
-            },
-            "examples": {
-              "application/json": {
-                "id": 1,
-                "name": "get food",
-                "completed": false,
-                "completed_at": "1955-04-23T13:22:52.685Z",
-                "created_at": "1994-11-05T03:26:51.471Z",
-                "updated_at": "1989-07-29T11:30:06.701Z"
-              }
-            }
-          }
-        }
-      }
-    }
-  }
-}
diff --git a/src/__tests__/spectral.jest.test.ts b/src/__tests__/spectral.jest.test.ts
index fa816aa32..1a39ed297 100644
--- a/src/__tests__/spectral.jest.test.ts
+++ b/src/__tests__/spectral.jest.test.ts
@@ -5,7 +5,6 @@ import * as nock from 'nock';
 import * as path from 'path';
 
 import { Document } from '../document';
-import { isOpenApiv2 } from '../formats';
 import { pattern } from '../functions/pattern';
 import * as Parsers from '../parsers';
 import { httpAndFileResolver } from '../resolvers/http-and-file';
@@ -97,93 +96,57 @@ describe('Spectral', () => {
   });
 
   test('should report issues for correct files with correct ranges and paths', async () => {
-    const documentUri = normalize(path.join(__dirname, './__fixtures__/document-with-external-refs.oas2.json'));
+    const documentUri = normalize(path.join(__dirname, './__fixtures__/document-with-external-refs.json'));
     const spectral = new Spectral({ resolver: httpAndFileResolver });
-    await spectral.loadRuleset('spectral:oas');
-    spectral.registerFormat('oas2', isOpenApiv2);
+    spectral.setRules({
+      'requires-type': {
+        given: ['$..allOf', '$.empty'],
+        then: {
+          field: 'type',
+          function: 'truthy',
+        },
+      },
+    });
     const document = new Document(fs.readFileSync(documentUri, 'utf8'), Parsers.Json, documentUri);
 
     const results = await spectral.run(document);
 
-    expect(results).toEqual(
-      expect.arrayContaining([
-        expect.objectContaining({
-          code: 'oas2-schema',
-          path: ['paths', '/todos/{todoId}', 'get', 'responses', '200', 'description'],
-          range: {
-            end: {
-              character: 29,
-              line: 17,
-            },
-            start: {
-              character: 27,
-              line: 17,
-            },
-          },
-          source: documentUri,
-        }),
-        expect.objectContaining({
-          code: 'oas2-schema',
-          path: [],
-          range: {
-            end: {
-              character: 1,
-              line: 37,
-            },
-            start: {
-              character: 0,
-              line: 0,
-            },
+    expect(results).toEqual([
+      {
+        code: 'requires-type',
+        message: '`empty.type` property is not truthy',
+        path: ['empty'],
+        range: {
+          end: {
+            character: 3,
+            line: 6,
           },
-          source: expect.stringContaining('__fixtures__/models/todo-full.v1.json'),
-        }),
-        expect.objectContaining({
-          code: 'path-params',
-          path: ['paths', '/todos/{todoId}', 'get'],
-          range: {
-            end: {
-              character: 7,
-              line: 33,
-            },
-            start: {
-              character: 13,
-              line: 11,
-            },
+          start: {
+            character: 11,
+            line: 4,
           },
-          source: documentUri,
-        }),
-        expect.objectContaining({
-          code: 'info-contact',
-          path: ['info'],
-          range: {
-            end: {
-              character: 3,
-              line: 6,
-            },
-            start: {
-              character: 10,
-              line: 2,
-            },
+        },
+        severity: DiagnosticSeverity.Warning,
+        source: documentUri,
+      },
+      {
+        code: 'requires-type',
+        message: '`allOf.type` property is not truthy',
+        path: ['allOf'],
+        range: {
+          end: {
+            character: 3,
+            line: 33,
           },
-          source: documentUri,
-        }),
-        expect.objectContaining({
-          code: 'operation-description',
-          path: ['paths', '/todos/{todoId}', 'get'],
-          range: {
-            end: {
-              character: 7,
-              line: 33,
-            },
-            start: {
-              character: 13,
-              line: 11,
-            },
+          start: {
+            character: 11,
+            line: 3,
           },
-          source: documentUri,
-        }),
-      ]),
-    );
+        },
+        severity: DiagnosticSeverity.Warning,
+        source: expect.stringContaining('__fixtures__/models/todo-full.v1.json'),
+      },
+    ]);
   });
 
   test('properly decorates results with metadata pertaining to the document being linted', async () => {
diff --git a/src/documentInventory.ts b/src/documentInventory.ts
index 31eae63a3..c9c35b7a6 100644
--- a/src/documentInventory.ts
+++ b/src/documentInventory.ts
@@ -109,12 +109,21 @@ export class DocumentInventory {
         if ($ref === null) return null;
 
         const scopedPath = [...safePointerToPath($ref), ...newPath];
-        let resolvedDoc;
+        let resolvedDoc = this.document;
 
         if (isLocalRef($ref)) {
           resolvedDoc = source === this.document.source ? this.document : this.referencedDocuments[source];
         } else {
-          const extractedSource = extractSourceFromRef($ref)!;
+          const extractedSource = extractSourceFromRef($ref);
+
+          if (extractedSource === null) {
+            return {
+              document: resolvedDoc,
+              path: getClosestJsonPath(resolvedDoc.data, path),
+              missingPropertyPath: path,
+            };
+          }
+
           source = isAbsoluteRef(extractedSource) ? extractedSource : resolve(source, '..', extractedSource);
 
           resolvedDoc = source === this.document.source ? this.document : this.referencedDocuments[source];