diff --git a/src/Trait.ts b/src/Trait.ts
index fbc5f90..91df43a 100644
--- a/src/Trait.ts
+++ b/src/Trait.ts
@@ -4,7 +4,7 @@ import { TraitExpression } from "./TraitExpression"
 import { ExtendFn, SimplifyFn, StaticMembers, StaticMembersFn } from "./util"
 
 
-export type AddAbstractToImplClass<
+type AddAbstractToImplClass<
     ImplClass      extends Class<object, []>,
     Abstract       extends object,
     StaticAbstract extends object,
diff --git a/src/TraitBuilder.ts b/src/TraitBuilder.ts
index 94f7a53..a825162 100644
--- a/src/TraitBuilder.ts
+++ b/src/TraitBuilder.ts
@@ -5,9 +5,30 @@ import { TraitExpression } from "./TraitExpression"
 import { ExtendFn, SimplifyFn, StaticMembers } from "./util"
 
 
-export type TraitApplierSuperTag = "@thilawyn/traitify-ts/Super"
+type SuperAbstract<SuperExpression, Abstract> = (
+    Pipe<SuperExpression, [
+        TraitExpression.TraitsFn,
+        Tuples.Map<Trait.OwnAbstractFn>,
+        Tuples.Append<Abstract>,
+        ExtendFn,
+        SimplifyFn,
+    ]>
+)
 
-export type RemoveAbstractFromImplClass<
+type SuperStaticAbstract<SuperExpression, StaticAbstract> = (
+    Pipe<SuperExpression, [
+        TraitExpression.TraitsFn,
+        Tuples.Map<Trait.OwnStaticAbstractFn>,
+        Tuples.Append<StaticAbstract>,
+        ExtendFn,
+        SimplifyFn,
+    ]>
+)
+
+
+type TraitApplierSuperTag = "@thilawyn/traitify-ts/Super"
+
+type RemoveAbstractFromImplClass<
     ImplClassWithAbstract extends (
         Class<Abstract, []> &
         StaticAbstract &
@@ -40,7 +61,7 @@ export class TraitBuilder<
         private readonly traitApply:            (Super: AbstractClass<object>) => ImplClass,
     ) {}
 
-    abstract<A extends Abstract>() {
+    abstract<A extends SuperAbstract<SuperExpression, Abstract>>() {
         return new TraitBuilder(
             this.traitSuperExpression,
             {} as A,
@@ -49,16 +70,10 @@ export class TraitBuilder<
         )
     }
 
-    extendAbstract<A extends Abstract>(
+    extendAbstract<A extends SuperAbstract<SuperExpression, Abstract>>(
         _: (
             Super: AbstractClass<
-                Pipe<SuperExpression, [
-                    TraitExpression.TraitsFn,
-                    Tuples.Map<Trait.OwnAbstractFn>,
-                    Tuples.Append<Abstract>,
-                    ExtendFn,
-                    SimplifyFn,
-                ]>
+                SuperAbstract<SuperExpression, Abstract>
             >
         ) => AbstractClass<A, []>
     ) {
@@ -70,7 +85,7 @@ export class TraitBuilder<
         )
     }
 
-    staticAbstract<A extends StaticAbstract>() {
+    staticAbstract<A extends SuperStaticAbstract<SuperExpression, StaticAbstract>>() {
         return new TraitBuilder(
             this.traitSuperExpression,
             this.traitAbstract,
@@ -79,15 +94,9 @@ export class TraitBuilder<
         )
     }
 
-    extendStaticAbstract<A extends StaticAbstract>(
+    extendStaticAbstract<A extends SuperStaticAbstract<SuperExpression, StaticAbstract>>(
         _: (Super: AbstractClass<
-            Pipe<SuperExpression, [
-                TraitExpression.TraitsFn,
-                Tuples.Map<Trait.OwnStaticAbstractFn>,
-                Tuples.Append<StaticAbstract>,
-                ExtendFn,
-                SimplifyFn,
-            ]>
+            SuperStaticAbstract<SuperExpression, StaticAbstract>
         >) => AbstractClass<A, []>
     ) {
         return new TraitBuilder(
@@ -101,7 +110,7 @@ export class TraitBuilder<
     implement<
         ImplClassWithAbstract extends (
             Class<Abstract, []> &
-            StaticAbstract &
+            SuperStaticAbstract<SuperExpression, StaticAbstract> &
             { _tag: TraitApplierSuperTag }
         )
     >(