diff --git a/src/ByteCode/ClassFile/Generator.hs b/src/ByteCode/ClassFile/Generator.hs
index 866c375..69382b3 100644
--- a/src/ByteCode/ClassFile/Generator.hs
+++ b/src/ByteCode/ClassFile/Generator.hs
@@ -206,7 +206,7 @@ assembleMethod (MethodDeclaration _ name _ (TypedStatement _ (Block statements))
             (constants_a, ops_a) = foldr assembleStatement (constants, ops) statements
             init_ops = [Opaload 0, Opinvokespecial 2]
         in
-            (constants_a, init_ops ++ ops_a)
+            (constants_a, init_ops ++ ops_a ++ [Opreturn])
     | otherwise = let
             (constants_a, ops_a) = foldr assembleStatement (constants, ops) statements
             init_ops = [Opaload 0]
@@ -221,6 +221,15 @@ assembleStatement (TypedStatement stype (Return expr)) (constants, ops) = case e
             (expr_constants, expr_ops) = assembleExpression expr (constants, ops)
         in  
             (expr_constants, expr_ops ++ [returnOperation stype])
+assembleStatement (TypedStatement _ (Block statements)) (constants, ops) =
+    foldr assembleStatement (constants, ops) statements
+assembleStatement (TypedStatement _ (If expr if_stmt else_stmt)) (constants, ops) = let
+        (constants_cmp, ops_cmp) = assembleExpression expr (constants, [])
+        (constants_ifa, ops_ifa) = assembleStatement if_stmt (constants_cmp, [])
+        skip_length = sum (map opcodeEncodingLength ops_ifa)
+    in
+        (constants_ifa, ops ++ ops_cmp ++ [Opsipush 0, Opif_icmpeq skip_length] ++ ops_ifa)
+
 
 assembleExpression :: Assembler Expression
 assembleExpression (TypedExpression _ (BinaryOperation op a b)) (constants, ops)
diff --git a/src/Main.hs b/src/Main.hs
index c9f5c18..858d5bb 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -9,7 +9,9 @@ import ByteCode.ClassFile
 import Data.ByteString (pack, writeFile)
 
 main = do
-    let untypedAST = parse $ alexScanTokens "class Testklasse {Testklasse(){} boolean something(){return 5 + 8 - 12 * 22 > 9 - 2 + 3;}}"
+    file <- readFile "Testklasse.java"
+
+    let untypedAST = parse $ alexScanTokens file
     let typedAST = head (typeCheckCompilationUnit untypedAST)
     let abstractClassFile = classBuilder typedAST emptyClassFile
     let assembledClassFile = pack (serialize abstractClassFile)