diff --git a/CMakeLists.txt b/CMakeLists.txt
index eb086b3..aea9756 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -121,3 +121,4 @@ endfunction()
 add_sample(hello_world)
 add_sample(sum)
 add_sample(erc20)
+add_sample(disassembler)
diff --git a/include/eEVM/disassembler.h b/include/eEVM/disassembler.h
index a70f4da..f88e29d 100644
--- a/include/eEVM/disassembler.h
+++ b/include/eEVM/disassembler.h
@@ -71,14 +71,15 @@ namespace eevm
   inline std::ostream& operator<<(std::ostream& os, const Instr& i)
   {
     os << fmt::format(
-      "{}: {}{} ({:02x} {:02x}); {}",
+      "{:>5}: {}{} [{:02x}{}]; {}",
       i.pc,
       i.op.mnemonic,
       i.op.has_immediate() ?
-        fmt::format(" 0x{}", to_lower_hex_str(i.get_immediate())) :
+        fmt::format(" {}", to_lower_hex_str(i.get_immediate())) :
         "",
       (int)i.op.opcode,
-      fmt::join(i.raw_imm, " "),
+      i.raw_imm.size() > 0 ? fmt::format(" {:02x}", fmt::join(i.raw_imm, " ")) :
+                             "",
       i.comment);
     return os;
   }
@@ -124,7 +125,13 @@ namespace eevm
         const auto op = getOp((Opcode)opcode);
         const auto bytes_left = prog.cend() - it;
         if (bytes_left < op.immediate_bytes)
-          throw std::out_of_range("Immediate exceeds instruction stream.");
+          throw std::out_of_range(fmt::format(
+            "Immediate exceeds instruction stream (op {} at "
+            "instruction {} wants {} bytes, only {} remain)",
+            op.mnemonic,
+            (size_t)(it - prog.cbegin()),
+            op.immediate_bytes,
+            bytes_left));
 
         auto instr = std::make_unique<Instr>(
           op, pc, std::vector<uint8_t>(it, it + op.immediate_bytes));
diff --git a/samples/disassembler/main.cpp b/samples/disassembler/main.cpp
new file mode 100644
index 0000000..394329a
--- /dev/null
+++ b/samples/disassembler/main.cpp
@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#include "eEVM/disassembler.h"
+
+#include <fmt/format_header_only.h>
+#include <iostream>
+
+int usage(const char* bin_name)
+{
+  std::cout << fmt::format("Usage: {} hex_bytecode", bin_name) << std::endl;
+  std::cout << "Prints disassembly of argument" << std::endl;
+  return 1;
+}
+
+int main(int argc, char** argv)
+{
+  if (argc != 2)
+  {
+    return usage(argv[0]);
+  }
+
+  const std::vector<uint8_t> code = eevm::to_bytes(argv[1]);
+
+  const auto dis = eevm::Disassembler::dis(code);
+
+  std::cout << dis << std::endl;
+
+  return 0;
+}