diff --git a/src/traits/ZodSchemaObject.ts b/src/traits/ZodSchemaObject.ts
index 860c68a..fcecae9 100644
--- a/src/traits/ZodSchemaObject.ts
+++ b/src/traits/ZodSchemaObject.ts
@@ -49,10 +49,12 @@ export const ZodSchemaObject = <
 
 
         static create<
-            Self     extends StaticMembers<ImplStaticThis<typeof ZodSchemaObject>>,
-            Instance extends Values,
+            Instance extends Values
         >(
-            this: Class<Instance, [values: Values]> & Self,
+            this: (
+                Class<Instance, [values: Values]> &
+                StaticMembers<ImplStaticThis<typeof ZodSchemaObject>>
+            ),
             ...[values, params]: NewZodSchemaInstanceArgs<PartialValues>
         ) {
             return this
@@ -61,10 +63,12 @@ export const ZodSchemaObject = <
         }
 
         static createPromise<
-            Self     extends StaticMembers<ImplStaticThis<typeof ZodSchemaObject>>,
-            Instance extends Values,
+            Instance extends Values
         >(
-            this: Class<Instance, [values: Values]> & Self,
+            this: (
+                Class<Instance, [values: Values]> &
+                StaticMembers<ImplStaticThis<typeof ZodSchemaObject>>
+            ),
             ...[values, params]: NewZodSchemaInstanceArgs<PartialValues>
         ) {
             return this
@@ -73,10 +77,12 @@ export const ZodSchemaObject = <
         }
 
         static createEffect<
-            Self     extends StaticMembers<ImplStaticThis<typeof ZodSchemaObject>>,
-            Instance extends Values,
+            Instance extends Values
         >(
-            this: Class<Instance, [values: Values]> & Self,
+            this: (
+                Class<Instance, [values: Values]> &
+                StaticMembers<ImplStaticThis<typeof ZodSchemaObject>>
+            ),
             ...[values, params]: NewZodSchemaInstanceArgs<PartialValues>
         ) {
             return parseZodSchemaEffect(