diff --git a/src/de/dhbwstuttgart/typinference/unify/model/ExtendsType.java b/src/de/dhbwstuttgart/typinference/unify/model/ExtendsType.java
index e9dbc7c07..763f3107e 100644
--- a/src/de/dhbwstuttgart/typinference/unify/model/ExtendsType.java
+++ b/src/de/dhbwstuttgart/typinference/unify/model/ExtendsType.java
@@ -3,6 +3,7 @@ package de.dhbwstuttgart.typinference.unify.model;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unifynew.Unifier;
 
 public final class ExtendsType extends Type {
 	private Type extendedType;
@@ -49,4 +50,9 @@ public final class ExtendsType extends Type {
 		ExtendsType other = (ExtendsType) obj;
 		return other.getExtendedType().equals(extendedType);
 	}
+
+	@Override
+	public Type applyToTypeParams(Unifier unif) {
+		return new ExtendsType(extendedType.applyToTypeParams(unif));
+	}
 }
diff --git a/src/de/dhbwstuttgart/typinference/unify/model/PlaceholderType.java b/src/de/dhbwstuttgart/typinference/unify/model/PlaceholderType.java
index dd40ab23b..53d5eab3f 100644
--- a/src/de/dhbwstuttgart/typinference/unify/model/PlaceholderType.java
+++ b/src/de/dhbwstuttgart/typinference/unify/model/PlaceholderType.java
@@ -3,6 +3,7 @@ package de.dhbwstuttgart.typinference.unify.model;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unifynew.Unifier;
 
 public final class PlaceholderType extends Type{
 	
@@ -32,4 +33,9 @@ public final class PlaceholderType extends Type{
 		
 		return ((PlaceholderType) obj).getName().equals(typeName);
 	}
+
+	@Override
+	public Type applyToTypeParams(Unifier unif) {
+		return this;
+	}
 }
diff --git a/src/de/dhbwstuttgart/typinference/unify/model/SimpleType.java b/src/de/dhbwstuttgart/typinference/unify/model/SimpleType.java
index 292289779..370f472bd 100644
--- a/src/de/dhbwstuttgart/typinference/unify/model/SimpleType.java
+++ b/src/de/dhbwstuttgart/typinference/unify/model/SimpleType.java
@@ -3,11 +3,16 @@ package de.dhbwstuttgart.typinference.unify.model;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unifynew.Unifier;
 
 public final class SimpleType extends Type {
 	public SimpleType(String name, Type... typeParams) {
 		super(name, new TypeParams(typeParams));
 	}
+	
+	private SimpleType(String name, TypeParams params) {
+		super(name, params);
+	}
 
 	@Override
 	public Set<Type> smArg(IFiniteClosure fc) {
@@ -36,4 +41,9 @@ public final class SimpleType extends Type {
 
 		return other.getTypeParams().equals(typeParams);
 	}
+
+	@Override
+	public Type applyToTypeParams(Unifier unif) {
+		return new SimpleType(typeName, typeParams.apply(unif));
+	}
 }
diff --git a/src/de/dhbwstuttgart/typinference/unify/model/SuperType.java b/src/de/dhbwstuttgart/typinference/unify/model/SuperType.java
index 2148e0dfa..6e55a9f33 100644
--- a/src/de/dhbwstuttgart/typinference/unify/model/SuperType.java
+++ b/src/de/dhbwstuttgart/typinference/unify/model/SuperType.java
@@ -3,6 +3,7 @@ package de.dhbwstuttgart.typinference.unify.model;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unifynew.Unifier;
 
 public final class SuperType extends Type {
 	
@@ -50,4 +51,9 @@ public final class SuperType extends Type {
 		SuperType other = (SuperType) obj;
 		return other.getSuperedType().equals(superedType);
 	}
+
+	@Override
+	public Type applyToTypeParams(Unifier unif) {
+		return new SuperType(superedType.applyToTypeParams(unif));
+	}
 }
diff --git a/src/de/dhbwstuttgart/typinference/unify/model/Type.java b/src/de/dhbwstuttgart/typinference/unify/model/Type.java
index 3da9dbcd0..b929d3c13 100644
--- a/src/de/dhbwstuttgart/typinference/unify/model/Type.java
+++ b/src/de/dhbwstuttgart/typinference/unify/model/Type.java
@@ -3,6 +3,7 @@ package de.dhbwstuttgart.typinference.unify.model;
 import java.util.Set;
 
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unifynew.Unifier;
 
 public abstract class Type {
 	
@@ -31,6 +32,8 @@ public abstract class Type {
 	
 	public abstract Set<Type> grArg(IFiniteClosure fc);
 	
+	public abstract Type applyToTypeParams(Unifier unif);
+	
 	@Override
 	public String toString() {
 		String params = "";
diff --git a/src/de/dhbwstuttgart/typinference/unify/model/TypeParams.java b/src/de/dhbwstuttgart/typinference/unify/model/TypeParams.java
index fe8dff83f..fb8fcb53a 100644
--- a/src/de/dhbwstuttgart/typinference/unify/model/TypeParams.java
+++ b/src/de/dhbwstuttgart/typinference/unify/model/TypeParams.java
@@ -28,9 +28,11 @@ public final class TypeParams implements Iterable<Type>{
 		return typeParams.length == 0;
 	}
 	
-	public void apply(Unifier u) {
+	public TypeParams apply(Unifier unif) {
+		Type[] newParams = new Type[typeParams.length];
 		for(int i = 0; i < typeParams.length; i++)
-			typeParams[i] = u.apply(typeParams[i]);
+			newParams[i] = typeParams[i].applyToTypeParams(unif);
+		return new TypeParams(newParams);
 	}
 	
 	public boolean contains(Type t) {