diff --git a/.changeset/tiny-cameras-battle.md b/.changeset/tiny-cameras-battle.md
new file mode 100644
index 00000000..565afe8a
--- /dev/null
+++ b/.changeset/tiny-cameras-battle.md
@@ -0,0 +1,5 @@
+---
+'gql.tada': patch
+---
+
+Remove redundant constraint on `IntrospectionQuery` data. When the full type is used as an `extends`, the input type (which can be a huge schema), is checked against this type, which forces a full evaluation. This means that TypeScript may spend multiple seconds in `recursiveTypeRelatedTo`. This work has been eliminated and should help performance.
diff --git a/src/__tests__/fixtures/simpleSchema.ts b/src/__tests__/fixtures/simpleSchema.ts
index 5a2056c8..a16c3d12 100644
--- a/src/__tests__/fixtures/simpleSchema.ts
+++ b/src/__tests__/fixtures/simpleSchema.ts
@@ -7,11 +7,9 @@ export type simpleSchema = {
     Query: {
       kind: 'OBJECT';
       name: 'Query';
-      interfaces: never;
       fields: {
         todos: {
           name: 'todos';
-          args: any;
           type: {
             kind: 'LIST';
             name: null;
@@ -24,7 +22,6 @@ export type simpleSchema = {
         };
         latestTodo: {
           name: 'latestTodo';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -37,7 +34,6 @@ export type simpleSchema = {
         };
         test: {
           name: 'test';
-          args: any;
           type: {
             kind: 'UNION';
             name: 'Search';
@@ -66,7 +62,6 @@ export type simpleSchema = {
       fields: {
         id: {
           name: 'id';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -79,7 +74,6 @@ export type simpleSchema = {
         };
         text: {
           name: 'text';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -92,7 +86,6 @@ export type simpleSchema = {
         };
         complete: {
           name: 'complete';
-          args: any;
           type: {
             kind: 'SCALAR';
             name: 'Boolean';
@@ -101,7 +94,6 @@ export type simpleSchema = {
         };
         author: {
           name: 'author';
-          args: any;
           type: {
             kind: 'OBJECT';
             name: 'Author';
@@ -110,7 +102,6 @@ export type simpleSchema = {
         };
         maxLength: {
           name: 'maxLength';
-          args: any;
           type: {
             kind: 'SCALAR';
             name: 'Int';
@@ -118,7 +109,6 @@ export type simpleSchema = {
           };
         };
       };
-      interfaces: 'ITodo';
     };
 
     BigTodo: {
@@ -127,7 +117,6 @@ export type simpleSchema = {
       fields: {
         id: {
           name: 'id';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -140,7 +129,6 @@ export type simpleSchema = {
         };
         text: {
           name: 'text';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -153,7 +141,6 @@ export type simpleSchema = {
         };
         complete: {
           name: 'complete';
-          args: any;
           type: {
             kind: 'SCALAR';
             name: 'Boolean';
@@ -162,7 +149,6 @@ export type simpleSchema = {
         };
         author: {
           name: 'author';
-          args: any;
           type: {
             kind: 'OBJECT';
             name: 'Author';
@@ -171,7 +157,6 @@ export type simpleSchema = {
         };
         wallOfText: {
           name: 'wallOfText';
-          args: any;
           type: {
             kind: 'SCALAR';
             name: 'String';
@@ -179,18 +164,15 @@ export type simpleSchema = {
           };
         };
       };
-      interfaces: 'ITodo';
     };
 
     ITodo: {
       kind: 'INTERFACE';
       name: 'ITodo';
-      interfaces: never;
       possibleTypes: 'BigTodo' | 'SmallTodo';
       fields: {
         id: {
           name: 'id';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -203,7 +185,6 @@ export type simpleSchema = {
         };
         text: {
           name: 'text';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -216,7 +197,6 @@ export type simpleSchema = {
         };
         complete: {
           name: 'complete';
-          args: any;
           type: {
             kind: 'SCALAR';
             name: 'Boolean';
@@ -225,7 +205,6 @@ export type simpleSchema = {
         };
         author: {
           name: 'author';
-          args: any;
           type: {
             kind: 'OBJECT';
             name: 'Author';
@@ -274,11 +253,9 @@ export type simpleSchema = {
     NoTodosError: {
       kind: 'OBJECT';
       name: 'NoTodosError';
-      interfaces: never;
       fields: {
         message: {
           name: 'message';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -295,11 +272,9 @@ export type simpleSchema = {
     Todo: {
       kind: 'OBJECT';
       name: 'Todo';
-      interfaces: never;
       fields: {
         id: {
           name: 'id';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -312,7 +287,6 @@ export type simpleSchema = {
         };
         text: {
           name: 'text';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -325,7 +299,6 @@ export type simpleSchema = {
         };
         complete: {
           name: 'complete';
-          args: any;
           type: {
             kind: 'SCALAR';
             name: 'Boolean';
@@ -334,7 +307,6 @@ export type simpleSchema = {
         };
         test: {
           name: 'test';
-          args: any;
           type: {
             kind: 'ENUM';
             name: 'test';
@@ -343,7 +315,6 @@ export type simpleSchema = {
         };
         author: {
           name: 'author';
-          args: any;
           type: {
             kind: 'OBJECT';
             name: 'Author';
@@ -376,11 +347,9 @@ export type simpleSchema = {
     Author: {
       kind: 'OBJECT';
       name: 'Author';
-      interfaces: never;
       fields: {
         id: {
           name: 'id';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -393,7 +362,6 @@ export type simpleSchema = {
         };
         name: {
           name: 'name';
-          args: any;
           type: {
             kind: 'NON_NULL';
             name: null;
@@ -406,7 +374,6 @@ export type simpleSchema = {
         };
         known: {
           name: 'known';
-          args: any;
           type: {
             kind: 'SCALAR';
             name: 'Boolean';
@@ -419,11 +386,9 @@ export type simpleSchema = {
     Mutation: {
       kind: 'OBJECT';
       name: 'Mutation';
-      interfaces: never;
       fields: {
         toggleTodo: {
           name: 'toggleTodo';
-          args: any;
           type: {
             kind: 'OBJECT';
             name: 'Todo';
@@ -432,7 +397,6 @@ export type simpleSchema = {
         };
         updateTodo: {
           name: 'updateTodo';
-          args: any;
           type: {
             kind: 'SCALAR';
             name: 'Boolean';
@@ -445,11 +409,9 @@ export type simpleSchema = {
     Subscription: {
       kind: 'OBJECT';
       name: 'Subscription';
-      interfaces: never;
       fields: {
         newTodo: {
           name: 'newTodo';
-          args: any;
           type: {
             kind: 'OBJECT';
             name: 'Todo';
diff --git a/src/introspection.ts b/src/introspection.ts
index bef434bc..264b6ffe 100644
--- a/src/introspection.ts
+++ b/src/introspection.ts
@@ -17,17 +17,20 @@ interface IntrospectionSchema {
   readonly queryType: IntrospectionNamedTypeRef;
   readonly mutationType?: IntrospectionNamedTypeRef | null;
   readonly subscriptionType?: IntrospectionNamedTypeRef | null;
-  readonly types: readonly IntrospectionType[];
+  /* Usually this would be:
+    | IntrospectionScalarType
+    | IntrospectionObjectType
+    | IntrospectionInterfaceType
+    | IntrospectionUnionType
+    | IntrospectionEnumType
+    | IntrospectionInputObjectType;
+    However, this forces TypeScript to evaluate the type of an
+    entire introspection query, rather than accept its shape as-is.
+    So, instead, we constrain it to `any` here.
+  */
+  readonly types: readonly any[];
 }
 
-export type IntrospectionType =
-  | IntrospectionScalarType
-  | IntrospectionObjectType
-  | IntrospectionInterfaceType
-  | IntrospectionUnionType
-  | IntrospectionEnumType
-  | IntrospectionInputObjectType;
-
 interface IntrospectionScalarType {
   readonly kind: 'SCALAR';
   readonly name: string;
@@ -37,16 +40,20 @@ interface IntrospectionScalarType {
 export interface IntrospectionObjectType {
   readonly kind: 'OBJECT';
   readonly name: string;
-  readonly fields: readonly IntrospectionField[];
-  readonly interfaces: readonly IntrospectionNamedTypeRef[] | never;
+  // Usually this would be `IntrospectionField`.
+  // However, to save TypeScript some work, instead, we constraint it to `any` here.
+  readonly fields: readonly any[];
+  // The `interfaces` field isn't used. It's omitted here
 }
 
 interface IntrospectionInterfaceType {
   readonly kind: 'INTERFACE';
   readonly name: string;
-  readonly fields: readonly IntrospectionField[];
+  // Usually this would be `IntrospectionField`.
+  // However, to save TypeScript some work, instead, we constraint it to `any` here.
+  readonly fields: readonly any[];
   readonly possibleTypes: readonly IntrospectionNamedTypeRef[];
-  readonly interfaces?: readonly IntrospectionNamedTypeRef[] | null;
+  // The `interfaces` field isn't used. It's omitted here
 }
 
 interface IntrospectionUnionType {
@@ -92,8 +99,8 @@ export interface IntrospectionNamedTypeRef {
 
 export interface IntrospectionField {
   readonly name: string;
-  readonly args: readonly IntrospectionInputValue[];
   readonly type: IntrospectionTypeRef;
+  // The `args` field isn't used. It's omitted here
 }
 
 interface IntrospectionInputValue {
@@ -132,14 +139,12 @@ type mapField<T> = T extends IntrospectionField
   ? {
       name: T['name'];
       type: T['type'];
-      args: any;
     }
   : never;
 
 export type mapObject<T extends IntrospectionObjectType> = {
   kind: 'OBJECT';
   name: T['name'];
-  interfaces: T['interfaces'][number]['name'];
   fields: obj<{
     [P in T['fields'][number]['name']]: T['fields'][number] extends infer Field
       ? Field extends { readonly name: P }
@@ -158,7 +163,6 @@ export type mapInputObject<T extends IntrospectionInputObjectType> = {
 type mapInterface<T extends IntrospectionInterfaceType> = {
   kind: 'INTERFACE';
   name: T['name'];
-  interfaces: T['interfaces'] extends readonly any[] ? T['interfaces'][number]['name'] : never;
   possibleTypes: T['possibleTypes'][number]['name'];
   fields: obj<{
     [P in T['fields'][number]['name']]: T['fields'][number] extends infer Field
@@ -224,8 +228,8 @@ export type ScalarsLike = {
 
 export type IntrospectionLikeType = {
   query: string;
-  mutation: string | never;
-  subscription: string | never;
+  mutation?: any;
+  subscription?: any;
   types: { [name: string]: any };
 };