diff --git a/src/definitions/_types.ts b/src/definitions/_types.ts
index d7480821..ac914b07 100644
--- a/src/definitions/_types.ts
+++ b/src/definitions/_types.ts
@@ -156,7 +156,10 @@ export type NexusGraphQLInterfaceTypeConfig = WithExt<
 > & { interfaces: () => GraphQLInterfaceType[] }
 
 export interface NexusGraphQLSchema extends GraphQLSchema {
-  extensions: { nexus: NexusSchemaExtension }
+  extensions: {
+    nexus: NexusSchemaExtension
+    [attributeName: string]: unknown
+  }
 }
 
 export type NexusFeaturesInput = {
diff --git a/tests/makeSchema.spec.ts b/tests/makeSchema.spec.ts
index 59de9750..5ed0b6e4 100644
--- a/tests/makeSchema.spec.ts
+++ b/tests/makeSchema.spec.ts
@@ -1,4 +1,4 @@
-import { printSchema } from 'graphql'
+import { GraphQLSchema, printSchema } from 'graphql'
 import os from 'os'
 import path from 'path'
 import { objectType } from '../src'
@@ -151,4 +151,16 @@ describe('makeSchema', () => {
       expect(tsTypes).toContain(`import type { Context } from "./makeSchema.spec"`)
     })
   })
+
+  it('is compatible with GraphQL schema types', () => {
+    const someFn = (schema: GraphQLSchema) => {
+      return schema.toConfig()
+    }
+
+    const nexusSchema = makeSchema({
+      types: [],
+    })
+
+    someFn(nexusSchema)
+  })
 })
diff --git a/tests/typegenPrinterGlobals.spec.ts b/tests/typegenPrinterGlobals.spec.ts
index f86b7e94..5eb59037 100644
--- a/tests/typegenPrinterGlobals.spec.ts
+++ b/tests/typegenPrinterGlobals.spec.ts
@@ -19,7 +19,7 @@ describe('typegenPrinter: globals', () => {
       schema: path.join(__dirname, 'typegen-globals/schema.gen.graphql'),
     } as const
 
-    const schema = (await generateSchema({
+    const schema = await generateSchema({
       outputs,
       shouldGenerateArtifacts: true,
       types: [buildSchema(EXAMPLE_SDL)],
@@ -35,7 +35,7 @@ describe('typegenPrinter: globals', () => {
 
         return content.replace("'nexus'", `'../../src'`)
       },
-    })) as core.NexusGraphQLSchema
+    })
 
     metadata = new TypegenMetadata({
       outputs,