diff --git a/src/vm/stack.nim b/src/vm/stack.nim
index ca84ff489..3eac36ed4 100644
--- a/src/vm/stack.nim
+++ b/src/vm/stack.nim
@@ -170,7 +170,10 @@ proc dup*(stack: var Stack, position: int | UInt256) =
 
 
 proc getInt*(stack: Stack, position: int): UInt256 =
-  stack.values[position]
+  if stack.values.len <= position:
+    raise newException(InsufficientStack, &"No {position} item")
+  else:
+    stack.values[position]
 
 proc getBinary*(stack: Stack, position: int): Bytes =
   stack.values[position].toType(Bytes)
@@ -178,6 +181,9 @@ proc getBinary*(stack: Stack, position: int): Bytes =
 proc getString*(stack: Stack, position: int): string =
   stack.values[position].toType(string)
 
+proc peek*(stack: Stack): UInt256 =
+  stack.getInt(stack.values.len - 1)
+
 proc `$`*(stack: Stack): string =
   let values = stack.values.mapIt(&"  {$it}").join("\n")
   &"Stack:\n{values}"
diff --git a/tests/opcode_test.nim b/tests/opcode_test.nim
new file mode 100644
index 000000000..6101fdc29
--- /dev/null
+++ b/tests/opcode_test.nim
@@ -0,0 +1,60 @@
+import 
+  unittest, test_helpers,
+  constants, types, errors, logging, ttmath,
+  tables, parseutils, chain, vm_state, computation, opcode, opcode_table, utils / [header, padding], vm / [gas_meter, message, code_stream, stack], vm / forks / frontier / vm, db / [db_chain, state_db], db / backends / memory_backend
+
+proc testCode(code: string, gas: UInt256): BaseComputation =
+  var vm = newFrontierVM(Header(), newBaseChainDB(newMemoryDB()))
+  let header = Header()
+    # coinbase: "",
+    # difficulty: fixture{"env"}{"currentDifficulty"}.getHexadecimalInt.u256,
+    # blockNumber: fixture{"env"}{"currentNumber"}.getHexadecimalInt.u256,
+    # gasLimit: fixture{"env"}{"currentGasLimit"}.getHexadecimalInt.u256,
+    # timestamp: fixture{"env"}{"currentTimestamp"}.getHexadecimalInt)
+  
+  let message = newMessage(
+    to="", #fixture{"exec"}{"address"}.getStr,
+    sender="", #fixture{"exec"}{"caller"}.getStr,
+    value=0.u256,
+    data = @[],
+    code=code,
+    gas=gas,
+    gasPrice=1.u256)
+    # gasPrice=fixture{"exec"}{"gasPrice"}.getHexadecimalInt.u256,
+    #options=newMessageOptions(origin=fixture{"exec"}{"origin"}.getStr))
+
+  #echo fixture{"exec"}
+  var c = newCodeStreamFromUnescaped(code)
+  #if DEBUG:
+  c.displayDecompiled()
+
+  var computation = newBaseComputation(vm.state, message)
+  computation.accountsToDelete = initTable[string, string]()
+  computation.opcodes = OPCODE_TABLE
+  computation.precompiles = initTable[string, Opcode]()
+
+  computation = computation.applyComputation(vm.state, message)
+  result = computation
+
+suite "opcodes":
+  test "add":
+    var c = testCode("0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff01", 100_000.u256)
+    check(c.gasMeter.gasRemaining == 99_991.u256)
+    check(c.stack.peek == "115792089237316195423570985008687907853269984665640564039457584007913129639934".u256)
+#     let address = Address::from_str("0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6").unwrap();
+#   let code = "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff01600055".from_hex().unwrap();
+
+#   let mut params = ActionParams::default();
+#   params.address = address.clone();
+#   params.gas = U256::from(100_000);
+#   params.code = Some(Arc::new(code));
+#   let mut ext = FakeExt::new();
+
+#   let gas_left = {
+#     let mut vm = factory.create(params.gas);
+#     test_finalize(vm.exec(params, &mut ext)).unwrap()
+#   };
+
+#   assert_eq!(gas_left, U256::from(79_988));
+#   assert_store(&ext, 0, "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe");
+# }
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