diff --git a/src/main/java/de/dhbwstuttgart/target/generate/StatementToTargetExpression.java b/src/main/java/de/dhbwstuttgart/target/generate/StatementToTargetExpression.java
index c6ee9939..92f20b9d 100644
--- a/src/main/java/de/dhbwstuttgart/target/generate/StatementToTargetExpression.java
+++ b/src/main/java/de/dhbwstuttgart/target/generate/StatementToTargetExpression.java
@@ -1,5 +1,6 @@
 package de.dhbwstuttgart.target.generate;
 
+import de.dhbwstuttgart.exceptions.DebugException;
 import de.dhbwstuttgart.exceptions.NotImplementedException;
 import de.dhbwstuttgart.parser.NullToken;
 import de.dhbwstuttgart.parser.SyntaxTreeGenerator.AssignToLocal;
@@ -214,7 +215,7 @@ public class StatementToTargetExpression implements ASTVisitor {
             foundMethod = thisMethod.orElseGet(() -> findMethod(finalReceiverClass.getSuperClass().getName(), methodCall.name, signature).orElseThrow());
         } else if (!isFunNType) {
             receiverClass = converter.compiler.getClass(receiverName);
-            System.out.println(receiverClass.getClassName() + " " + signature);
+            if (receiverClass == null) throw new DebugException("Class " + receiverName + " does not exist!");
             foundMethod = findMethod(receiverName, methodCall.name, signature).orElseThrow();
         }