diff --git a/src/EVM/ABI.hs b/src/EVM/ABI.hs
index a7c846716..a51ba1e5b 100644
--- a/src/EVM/ABI.hs
+++ b/src/EVM/ABI.hs
@@ -328,19 +328,22 @@ abiTailSize x =
         _ -> internalError "impossible"
 
 abiHeadSize :: AbiValue -> Int
-abiHeadSize x =
-  case abiKind (abiValueType x) of
+abiHeadSize x = abiSizeType (abiValueType x)
+
+abiSizeType :: AbiType -> Int
+abiSizeType x =
+  case abiKind x of
     Dynamic -> 32
     Static ->
       case x of
-        AbiUInt _ _  -> 32
-        AbiInt  _ _  -> 32
-        AbiBytes n _ -> roundTo32Bytes n
-        AbiAddress _ -> 32
-        AbiBool _    -> 32
-        AbiTuple v   -> sum (abiHeadSize <$> v)
-        AbiArray _ _ xs -> sum (abiHeadSize <$> xs)
-        AbiFunction _ -> 32
+        AbiUIntType _  -> 32
+        AbiIntType  _  -> 32
+        AbiBytesType n -> roundTo32Bytes n
+        AbiAddressType -> 32
+        AbiBoolType    -> 32
+        AbiTupleType n  -> sum (abiSizeType <$> n)
+        AbiArrayType n t -> n*(abiSizeType t)
+        AbiFunctionType -> 32
         _ -> internalError "impossible"
 
 putAbiSeq :: Vector AbiValue -> Put
@@ -512,29 +515,20 @@ decodeBuf tpsOrig bufOrig = go tpsOrig bufOrig 0 NoVals
     go :: [AbiType] -> Expr Buf -> Int -> AbiVals -> AbiVals
     go [] _ _ ret = ret
     go [AbiStringType] buf off (SAbi acc) = MixAbi (acc, decodeStringArg off buf)
+    go [_] _ _ (SAbi _) = internalError "Currently we can only decode string as last dynamic type"
     go (x:_) _ _ _ | isDynamic x = internalError "Dynamic type must be last in the list"
-    go (_:tps) buf off (SAbi acc) =
-      let
-        v = readWord (Lit (unsafeInto off)) buf
-      in if not (isLitWord v) then go tps buf (off+32) (SAbi (acc++[v]))
-         else internalError "can't mix Symbolic and Concrete"
-    go (t:tps) buf off (CAbi acc) =
-      let v = readWord (Lit (unsafeInto off)) buf
+    go (t:ts) buf off (SAbi acc) =
+      let len = abiSizeType t
+          v = readBytes len (Lit (unsafeInto off)) buf
+      in go ts buf (off+len) (SAbi (acc++[v]))
+    go (t:ts) buf off (CAbi acc) | (not . isDynamic) t =
+      let len = abiSizeType t
+          v = readBytes len (Lit (unsafeInto off)) buf
           asBS = mconcat $ fmap word256Bytes (mapMaybe maybeLitWord [v])
       in case runGetOrFail (getAbiSeq 1 [t]) (BSLazy.fromStrict asBS) of
-        Right ("", _, args) -> go tps buf (off+32) $ CAbi (acc++(toList args))
+        Right ("", _, args) -> go ts buf (off+len) $ CAbi (acc++(toList args))
         _ -> NoVals
     go _ _ _ _ = internalError "decodeBuf: expected concrete buffer"
--- decodeBuf tps buf =
---   let
---     vs = decodeStaticArgs 0 (length tps) buf
---     asBS = mconcat $ fmap word256Bytes (mapMaybe maybeLitWord vs)
---   in if not (all isLitWord vs)
---      then SAbi vs
---      else case runGetOrFail (getAbiSeq (length tps) tps) (BSLazy.fromStrict asBS) of
---        Right ("", _, args) -> CAbi (toList args)
---        _ -> NoVals
--- decodeBuf _ _ = internalError "decodeBuf: expected concrete buffer"
 
 decodeStaticArgs :: Int -> Int -> Expr Buf -> [Expr EWord]
 decodeStaticArgs offset numArgs b =
@@ -542,8 +536,8 @@ decodeStaticArgs offset numArgs b =
 
 decodeStringArg :: Int -> Expr Buf -> AbiValue
 decodeStringArg offs (ConcreteBuf b) =
-  let len = forceLit $ readBytes 4 (Lit . unsafeInto $ offs) (ConcreteBuf b)
-      str = [readByte (Lit . unsafeInto $ (offs + 4 + (unsafeInto i))) (ConcreteBuf b) | i <- [0..len]]
+  let len = forceLit $ readBytes 32 (Lit . unsafeInto $ offs) (ConcreteBuf b)
+      str = [readByte (Lit . unsafeInto $ (offs + 32 + (unsafeInto i))) (ConcreteBuf b) | i <- [0..len]]
       bs = (map toLitByte str)
   in AbiString $ BS.pack bs
   where