diff --git a/src/main/java/de/maishai/typedast/typedclass/TypedConstructor.java b/src/main/java/de/maishai/typedast/typedclass/TypedConstructor.java
index 8942e3b..0abb847 100644
--- a/src/main/java/de/maishai/typedast/typedclass/TypedConstructor.java
+++ b/src/main/java/de/maishai/typedast/typedclass/TypedConstructor.java
@@ -65,11 +65,16 @@ public class TypedConstructor implements TypedNode {
 
     public void convertToBlock(TypedClass clas, Constructor unTypedConstructor) {
         this.typedBlock = new TypedBlock(clas, unTypedConstructor.block());
+        typeCheck(clas);
     }
 
     @Override
     public Type typeCheck(TypedClass clas) {
-        //TODO: check if return is there
+        type = typedBlock.typeCheck(clas);
+        if(type != Type.VOID){
+            throw new RuntimeException("Constructor must not habe a return statement");
+        }
+
         return type;
     }