diff --git a/src/effect/EffectSchemaTraitExpression.ts b/src/effect/EffectSchemaTraitExpression.ts
index 7f5dc9e..96a3b5c 100644
--- a/src/effect/EffectSchemaTraitExpression.ts
+++ b/src/effect/EffectSchemaTraitExpression.ts
@@ -8,7 +8,10 @@ import { Extend } from "../util"
 export class EffectSchemaTraitExpression<
     Superclass   extends S.Class<unknown, Fields, A, I, R, C, Inherited, Proto>,
     Fields       extends S.Struct.Fields,
-    A, I, R, C,
+    A,
+    I,
+    R,
+    C,
     Inherited    extends object,
     Proto,
 
@@ -24,7 +27,10 @@ export class EffectSchemaTraitExpression<
         S.Class<
             Self,
             Fields,
-            A, I, R, C,
+            A,
+            I,
+            R,
+            C,
             Simplify<
                 Extend<[
                     Inherited,
diff --git a/src/effect/EffectSchemaTraitExpressionBuilder.ts b/src/effect/EffectSchemaTraitExpressionBuilder.ts
index 051e0cb..fd9d063 100644
--- a/src/effect/EffectSchemaTraitExpressionBuilder.ts
+++ b/src/effect/EffectSchemaTraitExpressionBuilder.ts
@@ -1,14 +1,84 @@
 import { Schema as S } from "@effect/schema"
+import { Simplify } from "effect/Types"
 import { Trait } from "../Trait"
 import { TraitExpression } from "../TraitExpression"
 import { TraitExpressionBuilder } from "../TraitExpressionBuilder"
 import { spreadSupertraits } from "../spreadSupertraits"
 import { traitsUnique } from "../traitsUnique"
+import { StaticMembers } from "../util"
+
+
+export class EffectSchemaInitialTraitExpressionBuilder {
+    class<
+        Fields extends S.Struct.Fields
+    >(
+        identifier:    string,
+        fields:        Fields,
+        annotations?:  S.Annotations.Schema<unknown>,
+    ) {
+        return new EffectSchemaTraitExpressionBuilder(
+            S.Class<unknown>(identifier)(fields, annotations),
+            [],
+        )
+    }
+
+    taggedClass<
+        Tag    extends string,
+        Fields extends S.Struct.Fields,
+    >(
+        tag:           Tag,
+        fields:        Fields,
+        annotations?:  S.Annotations.Schema<unknown>,
+    ) {
+        return new EffectSchemaTraitExpressionBuilder(
+            S.TaggedClass<unknown>()(tag, fields, annotations),
+            [],
+        )
+    }
+
+    extends<
+        Super     extends S.Class<any, Fields, A, I, R, C, Inherited, Proto>,
+
+        Fields    extends S.Struct.Fields,
+        A,
+        I,
+        R,
+        C,
+        Inherited extends object,
+        Proto,
+
+        NewFields extends S.Struct.Fields,
+    >(
+        superclass:    Super | S.Class<any, Fields, A, I, R, C, Inherited, Proto>,
+        identifier:    string,
+        fields:        NewFields,
+        annotations?:  S.Annotations.Schema<unknown>,
+    ) {
+        return new EffectSchemaTraitExpressionBuilder<
+            Fields & NewFields,
+            Simplify<A & S.Struct.Type<NewFields>>,
+            Simplify<I & S.Struct.Encoded<NewFields>>,
+            R | S.Struct.Context<NewFields>,
+            Simplify<C & S.Struct.Type<NewFields>>,
+            InstanceType<Super>,
+            Proto,
+            StaticMembers<Super>,
+
+            readonly []
+        >(
+            superclass.extend<unknown>(identifier)(fields, annotations) as any,
+            [],
+        )
+    }
+}
 
 
 export class EffectSchemaTraitExpressionBuilder<
     Fields       extends S.Struct.Fields,
-    A, I, R, C,
+    A,
+    I,
+    R,
+    C,
     Inherited    extends object,
     Proto,
     Static       extends object,
@@ -21,42 +91,6 @@ export class EffectSchemaTraitExpressionBuilder<
     ) {}
 
 
-    class<NewFields extends S.Struct.Fields>(
-        identifier:    string,
-        fields:        NewFields,
-        annotations?:  S.Annotations.Schema<unknown>
-    ) {
-        return new EffectSchemaTraitExpressionBuilder(
-            S.Class<unknown>(identifier)(fields, annotations),
-            this.expressionTraits,
-        )
-    }
-
-
-    extends<
-        Super          extends S.Class<unknown, SuperFields, SuperA, SuperI, SuperR, SuperC, SuperInherited, SuperProto>,
-
-        SuperFields    extends S.Struct.Fields,
-        SuperA, SuperI, SuperR, SuperC,
-        SuperInherited extends object,
-        SuperProto,
-    >(
-        superclass: Super | S.Class<unknown, SuperFields, SuperA, SuperI, SuperR, SuperC, SuperInherited, SuperProto>
-    ) {
-        return new EffectSchemaTraitExpressionBuilder<
-            Super,
-            Traits,
-
-            SuperFields,
-            SuperA, SuperI, SuperR, SuperC,
-            SuperInherited,
-            SuperProto
-        >(
-            superclass as Super,
-            this.expressionTraits,
-        )
-    }
-
     expresses<
         const T extends readonly Trait<
             TraitExpression<
@@ -71,7 +105,10 @@ export class EffectSchemaTraitExpressionBuilder<
         ...traits: T
     ): EffectSchemaTraitExpressionBuilder<
         Fields,
-        A, I, R, C,
+        A,
+        I,
+        R,
+        C,
         Inherited,
         Proto,
         Static,
@@ -88,3 +125,6 @@ export class EffectSchemaTraitExpressionBuilder<
         )
     }
 }
+
+
+export const effectSchemaExpression = new EffectSchemaInitialTraitExpressionBuilder()