diff --git a/lib/services/schema-normalizer.service.spec.ts b/lib/services/schema-normalizer.service.spec.ts
index 57c64a0e..a67666e4 100644
--- a/lib/services/schema-normalizer.service.spec.ts
+++ b/lib/services/schema-normalizer.service.spec.ts
@@ -152,7 +152,7 @@ describe('Spec Helper', () => {
       });
 
       it('should remove $allOf field', () => {
-        expect(joined.allOf).toBeNull();
+        expect(joined.allOf).toBeUndefined();
       });
 
       it('should set type object', () => {
@@ -178,7 +178,7 @@ describe('Spec Helper', () => {
       });
 
       it('should remove $allOf field', () => {
-        expect(joined.allOf).toBeNull();
+        expect(joined.allOf).toBeUndefined();
       });
 
       it('should set type object', () => {
@@ -204,7 +204,7 @@ describe('Spec Helper', () => {
       });
 
       it('should remove $allOf field', () => {
-        expect(joined.allOf).toBeNull();
+        expect(joined.allOf).toBeUndefined();
       });
 
       it('should set type object', () => {
diff --git a/lib/services/schema-normalizer.service.ts b/lib/services/schema-normalizer.service.ts
index f599a73a..f60de630 100644
--- a/lib/services/schema-normalizer.service.ts
+++ b/lib/services/schema-normalizer.service.ts
@@ -116,7 +116,7 @@ export class AllOfMerger {
       subSchema._pointer = tmpPtr;
     }
     if (!hadDiscriminator) into.discriminator = null;
-    into.allOf = null;
+    delete into.allOf;
   }
 
   private static mergeObject(into, subSchema, allOfNumber) {
diff --git a/package.json b/package.json
index 2ceaf9e8..905baaf9 100644
--- a/package.json
+++ b/package.json
@@ -131,7 +131,7 @@
     "json-schema-ref-parser": "^3.3.1",
     "lunr": "^1.0.0",
     "mark.js": "^8.11.1",
-    "openapi-sampler": "^0.4.3",
+    "openapi-sampler": "1.0.0-beta.8",
     "perfect-scrollbar": "^0.8.1",
     "prismjs": "^1.8.1",
     "remarkable": "1.7.1",
diff --git a/yarn.lock b/yarn.lock
index 41f9cab7..636cf70a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4676,9 +4676,11 @@ ono@^4.0.2:
   dependencies:
     format-util "^1.0.3"
 
-openapi-sampler@^0.4.3:
-  version "0.4.3"
-  resolved "https://registry.yarnpkg.com/openapi-sampler/-/openapi-sampler-0.4.3.tgz#de3aa522f45744c8349f598d4d9b6f35caaf25b2"
+openapi-sampler@1.0.0-beta.8:
+  version "1.0.0-beta.8"
+  resolved "https://registry.yarnpkg.com/openapi-sampler/-/openapi-sampler-1.0.0-beta.8.tgz#bf43ff47737fc4e1f988d0e2082d49788f41dead"
+  dependencies:
+    json-pointer "^0.6.0"
 
 opener@~1.4.0:
   version "1.4.3"