diff --git a/src/ByteCode/ClassFile.hs b/src/ByteCode/ClassFile.hs
index 38cf88e..37481db 100644
--- a/src/ByteCode/ClassFile.hs
+++ b/src/ByteCode/ClassFile.hs
@@ -113,10 +113,10 @@ opcodeEncodingLength (Opinvokespecial _)    = 3
 opcodeEncodingLength (Opgoto _)             = 3
 opcodeEncodingLength (Opsipush _)           = 3
 opcodeEncodingLength (Opldc_w _)            = 3
-opcodeEncodingLength (Opaload _)            = 3
-opcodeEncodingLength (Opiload _)            = 3
-opcodeEncodingLength (Opastore _)           = 3
-opcodeEncodingLength (Opistore _)           = 3
+opcodeEncodingLength (Opaload _)            = 4
+opcodeEncodingLength (Opiload _)            = 4
+opcodeEncodingLength (Opastore _)           = 4
+opcodeEncodingLength (Opistore _)           = 4
 opcodeEncodingLength (Opputfield _)         = 3
 opcodeEncodingLength (Opgetfield _)         = 3
 
diff --git a/src/ByteCode/ClassFile/Generator.hs b/src/ByteCode/ClassFile/Generator.hs
index 2eabd67..adb4d6f 100644
--- a/src/ByteCode/ClassFile/Generator.hs
+++ b/src/ByteCode/ClassFile/Generator.hs
@@ -262,6 +262,14 @@ assembleStatement (constants, ops, lvars) (TypedStatement _ (If expr if_stmt els
         else_length = sum (map opcodeEncodingLength ops_elsea) + 3
     in
         (constants_ifa, ops ++ ops_cmp ++ [Opsipush 0, Opif_icmpeq if_length] ++ ops_ifa ++ [Opgoto else_length] ++ ops_elsea, lvars)
+assembleStatement (constants, ops, lvars) (TypedStatement _ (While expr stmt)) = let
+        (constants_cmp, ops_cmp, _) = assembleExpression (constants, [], lvars) expr
+        (constants_stmta, ops_stmta, _) = assembleStatement (constants_cmp, [], lvars) stmt
+        -- +3 because we insert 2 gotos, one for the comparison, one for the goto back to the comparison
+        stmt_length = sum (map opcodeEncodingLength ops_stmta) + 6
+        entire_length = stmt_length + sum (map opcodeEncodingLength ops_cmp)
+    in
+        (constants_stmta, ops ++ ops_cmp ++ [Opsipush 0, Opif_icmpeq stmt_length] ++ ops_stmta ++ [Opgoto (-entire_length)], lvars)
 assembleStatement (constants, ops, lvars) (TypedStatement _ (LocalVariableDeclaration (VariableDeclaration dtype name expr))) = let
         isPrimitive = elem dtype ["char", "boolean", "int"]
         (constants_init, ops_init, _) = case expr of