diff --git a/src/components/__tests__/__snapshots__/DiscriminatorDropdown.test.tsx.snap b/src/components/__tests__/__snapshots__/DiscriminatorDropdown.test.tsx.snap
index 2c76429342..2e689d7ae6 100644
--- a/src/components/__tests__/__snapshots__/DiscriminatorDropdown.test.tsx.snap
+++ b/src/components/__tests__/__snapshots__/DiscriminatorDropdown.test.tsx.snap
@@ -80,16 +80,12 @@ exports[`Components SchemaView discriminator should correctly render discriminat
             "options": "<<<filtered>>>",
             "pattern": undefined,
             "rawSchema": Object {
-              "allOf": undefined,
               "default": undefined,
-              "parentRefs": Array [],
               "type": "string",
             },
             "readOnly": false,
             "schema": Object {
-              "allOf": undefined,
               "default": undefined,
-              "parentRefs": Array [],
               "type": "string",
             },
             "title": "",
diff --git a/src/services/OpenAPIParser.ts b/src/services/OpenAPIParser.ts
index d757598201..869e89c53f 100644
--- a/src/services/OpenAPIParser.ts
+++ b/src/services/OpenAPIParser.ts
@@ -192,6 +192,14 @@ export class OpenAPIParser {
       parentRefs: [],
     };
 
+    // avoid mutating inner objects
+    if (receiver.properties !== undefined && typeof receiver.properties === 'object') {
+      receiver.properties = { ...receiver.properties };
+    }
+    if (receiver.items !== undefined && typeof receiver.items === 'object') {
+      receiver.items = { ...receiver.items };
+    }
+
     const allOfSchemas = schema.allOf.map(subSchema => {
       const resolved = this.deref(subSchema, forceCircular);
       const subRef = subSchema.$ref || undefined;