diff --git a/test/types/models.test.ts b/test/types/models.test.ts
index c6678a5a0d1..d31a447eee9 100644
--- a/test/types/models.test.ts
+++ b/test/types/models.test.ts
@@ -561,3 +561,11 @@ function findWithId() {
   TestModel.find(id);
   TestModel.findOne(id);
 }
+
+function gh12573ModelAny() {
+  const TestModel = model<any>('Test', new Schema({}));
+  const doc = new TestModel();
+  expectType<any>(doc);
+  const { fieldA } = doc;
+  expectType<any>(fieldA);
+}
diff --git a/types/index.d.ts b/types/index.d.ts
index 97663a46d84..f7cf20b31ac 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -551,7 +551,6 @@ declare module 'mongoose' {
   export type SchemaDefinitionType<T> = T extends Document ? Omit<T, Exclude<keyof Document, '_id' | 'id' | '__v'>> : T;
 
   // Helpers to simplify checks
-  type IfAny<IFTYPE, THENTYPE, ELSETYPE = IFTYPE> = 0 extends (1 & IFTYPE) ? THENTYPE : ELSETYPE;
   type IfUnknown<IFTYPE, THENTYPE> = unknown extends IFTYPE ? THENTYPE : IFTYPE;
 
   // tests for these two types are located in test/types/lean.test.ts
diff --git a/types/inferschematype.d.ts b/types/inferschematype.d.ts
index 27090b89eb4..3874e98b8a6 100644
--- a/types/inferschematype.d.ts
+++ b/types/inferschematype.d.ts
@@ -38,7 +38,7 @@ declare module 'mongoose' {
    * // result
    * type UserType = {userName?: string}
    */
-  type InferSchemaType<TSchema> = ObtainSchemaGeneric<TSchema, 'DocType'>;
+  type InferSchemaType<TSchema> = IfAny<TSchema, any, ObtainSchemaGeneric<TSchema, 'DocType'>>;
 
   /**
    * @summary Obtains schema Generic type by using generic alias.
diff --git a/types/utility.d.ts b/types/utility.d.ts
index bfc531aa8f2..e5567b37b28 100644
--- a/types/utility.d.ts
+++ b/types/utility.d.ts
@@ -1,4 +1,5 @@
 declare module 'mongoose' {
+  type IfAny<IFTYPE, THENTYPE, ELSETYPE = IFTYPE> = 0 extends (1 & IFTYPE) ? THENTYPE : ELSETYPE;
 
   type Unpacked<T> = T extends (infer U)[] ?
     U :