diff --git a/.changeset/ref-sibling-regression.md b/.changeset/ref-sibling-regression.md
new file mode 100644
index 0000000..1ef5ad6
--- /dev/null
+++ b/.changeset/ref-sibling-regression.md
@@ -0,0 +1,5 @@
+---
+"openapi-sampler": patch
+---
+
+Fixed a regression from 1.7.7: a `$ref` inside `allOf` was sampled as `null`, and `skipReadOnly`/`skipWriteOnly` ignored a `$ref` inside `oneOf` or `anyOf`.
diff --git a/src/allOf.js b/src/allOf.js
index f7d69da..a4d3d31 100644
--- a/src/allOf.js
+++ b/src/allOf.js
@@ -7,7 +7,8 @@ export function allOfSample(into, children, options, spec, context) {
   const subSamples = [];
 
   for (let subSchema of children) {
-    const { type, readOnly, writeOnly, value } = traverse({ type: res.type, ...subSchema }, options, spec, {
+    const childSchema = subSchema.$ref ? subSchema : { type: res.type, ...subSchema };
+    const { type, readOnly, writeOnly, value } = traverse(childSchema, options, spec, {
       ...context,
       isAllOfChild: true,
     });
diff --git a/src/traverse.js b/src/traverse.js
index b2632d1..fa4c73b 100644
--- a/src/traverse.js
+++ b/src/traverse.js
@@ -78,7 +78,9 @@ export function traverse(schema, options, spec, context) {
       ref = ref.substring(1);
     }
 
-    const { $ref: _, ...siblings } = schema;
+    const siblings = Object.fromEntries(
+      Object.entries(schema).filter(([key, value]) => key !== '$ref' && value !== undefined),
+    );
     const referenced = Object.keys(siblings).length && !shouldIgnoreRefSiblings(spec)
       ? mergeRefSiblings(JsonPointer.get(spec, ref), siblings)
       : JsonPointer.get(spec, ref);
diff --git a/test/integration.spec.js b/test/integration.spec.js
index 4ee1a01..4e662a5 100644
--- a/test/integration.spec.js
+++ b/test/integration.spec.js
@@ -939,6 +939,54 @@ describe('Integration', () => {
           expect(spec.components.schemas.Num).toEqual({ type: 'number' });
         }
       });
+
+      it('should apply a null sibling written in the document', () => {
+        result = sample({ $ref: '#/components/schemas/Num', default: null }, {}, refSiblingsSpec({ openapi: '3.1.0' }));
+        expect(result).toBeNull();
+      });
+
+      it('should not apply the type that allOf passes to its items to a $ref', () => {
+        for (const spec of [refSiblingsSpec({ openapi: '3.1.0' }), refSiblingsSpec({})]) {
+          result = sample({ allOf: [{ $ref: '#/components/schemas/Pet' }] }, {}, spec);
+          expect(result).toEqual({ name: 'string' });
+
+          result = sample({
+            allOf: [
+              { $ref: '#/components/schemas/Pet' },
+              { properties: { age: { type: 'integer' } } },
+            ]
+          }, {}, spec);
+          expect(result).toEqual({ name: 'string', age: 0 });
+        }
+      });
+
+      it('should keep readOnly and writeOnly of a $ref in oneOf and anyOf', () => {
+        for (const version of [{ openapi: '3.1.0' }, {}]) {
+          const spec = {
+            ...version,
+            components: {
+              schemas: {
+                Id: { type: 'string', readOnly: true },
+                Password: { type: 'string', writeOnly: true },
+              },
+            },
+          };
+          const schema = {
+            type: 'object',
+            properties: {
+              id: { oneOf: [{ $ref: '#/components/schemas/Id' }] },
+              password: { anyOf: [{ $ref: '#/components/schemas/Password' }] },
+              name: { type: 'string' },
+            },
+          };
+
+          result = sample(schema, { skipReadOnly: true }, spec);
+          expect(result).toEqual({ password: 'string', name: 'string' });
+
+          result = sample(schema, { skipWriteOnly: true }, spec);
+          expect(result).toEqual({ id: 'string', name: 'string' });
+        }
+      });
     });
   });