diff --git a/evmcc/evmcc.cpp b/evmcc/evmcc.cpp
index 9828d4876..5ee11abb1 100644
--- a/evmcc/evmcc.cpp
+++ b/evmcc/evmcc.cpp
@@ -196,7 +196,7 @@ int main(int argc, char** argv)
 			data.code = bytecode.data();
 
 			// BROKEN: env_* functions must be implemented & RuntimeData struct created
-			auto result = engine.run(std::move(module), &data, nullptr);
+			auto result = engine.run(std::move(module), &data, nullptr, bytecode);
 			return static_cast<int>(result);
 		}
 	}
diff --git a/libevmjit/Cache.cpp b/libevmjit/Cache.cpp
index 1dd6f1d9f..663c0d820 100644
--- a/libevmjit/Cache.cpp
+++ b/libevmjit/Cache.cpp
@@ -27,7 +27,7 @@ ExecBundle& Cache::registerExec(Cache::Key _key, ExecBundle&& _exec)
 	auto& map = getCacheMap();
 	auto r = map.insert(std::make_pair(_key, std::move(_exec)));
 	assert(r.second && "Updating cached objects not supported");
-	LOG() << "add  " << _key << "\n";
+	LOG() << "add\n";
 	return r.first->second;  // return exec, now owned by cache
 }
 
@@ -37,10 +37,10 @@ ExecBundle* Cache::findExec(Cache::Key _key)
 	auto it = map.find(_key);
 	if (it != map.end())
 	{
-		LOG() << "hit  " << _key << "\n";
+		LOG() << "hit\n";
 		return &it->second;
 	}
-	LOG() << "miss " << _key << "\n";
+	LOG() << "miss\n";
 	return nullptr;
 }
 
diff --git a/libevmjit/Cache.h b/libevmjit/Cache.h
index c9a74ea91..62875edac 100644
--- a/libevmjit/Cache.h
+++ b/libevmjit/Cache.h
@@ -12,16 +12,22 @@ namespace jit
 {
 
 /// A bundle of objects and information needed for a contract execution
-struct ExecBundle
+class ExecBundle
 {
+public:
 	std::unique_ptr<llvm::ExecutionEngine> engine;
 	llvm::Function* entryFunc = nullptr;
+
+	ExecBundle() = default;
+	ExecBundle(ExecBundle&&) = default;
+	ExecBundle(ExecBundle const&) = delete;
+	void operator=(ExecBundle) = delete;
 };
 
 class Cache
 {
 public:
-	using Key = void const*;
+	using Key = std::string;
 
 	static ExecBundle& registerExec(Key _key, ExecBundle&& _exec);
 	static ExecBundle* findExec(Key _key);
diff --git a/libevmjit/ExecutionEngine.cpp b/libevmjit/ExecutionEngine.cpp
index 719be9ac6..936899828 100644
--- a/libevmjit/ExecutionEngine.cpp
+++ b/libevmjit/ExecutionEngine.cpp
@@ -36,13 +36,13 @@ namespace jit
 ReturnCode ExecutionEngine::run(bytes const& _code, RuntimeData* _data, Env* _env)
 {
 	auto module = Compiler({}).compile(_code);
-	return run(std::move(module), _data, _env);
+	return run(std::move(module), _data, _env, _code);
 }
 
-ReturnCode ExecutionEngine::run(std::unique_ptr<llvm::Module> _module, RuntimeData* _data, Env* _env)
+ReturnCode ExecutionEngine::run(std::unique_ptr<llvm::Module> _module, RuntimeData* _data, Env* _env, bytes const& _code)
 {
-	auto key = _data->code;  // TODO: Change cache key
-	if (auto cachedExec = Cache::findExec(key))
+	std::string key{reinterpret_cast<char const*>(_code.data()), _code.size()};
+	if (auto cachedExec = Cache::findExec(std::move(key)))
 	{
 		return run(*cachedExec, _data, _env);
 	}
@@ -94,7 +94,7 @@ ReturnCode ExecutionEngine::run(std::unique_ptr<llvm::Module> _module, RuntimeDa
 	if (!exec.entryFunc)
 		return ReturnCode::LLVMLinkError;
 
-	auto& cachedExec = Cache::registerExec(_data->code, std::move(exec));
+	auto& cachedExec = Cache::registerExec(key, std::move(exec));
 	auto returnCode = run(cachedExec, _data, _env);
 
 	auto executionEndTime = std::chrono::high_resolution_clock::now();
diff --git a/libevmjit/ExecutionEngine.h b/libevmjit/ExecutionEngine.h
index 785e4efda..499aa894a 100644
--- a/libevmjit/ExecutionEngine.h
+++ b/libevmjit/ExecutionEngine.h
@@ -13,7 +13,7 @@ namespace eth
 {
 namespace jit
 {
-struct ExecBundle;
+class ExecBundle;
 
 class ExecutionEngine
 {
@@ -23,7 +23,7 @@ public:
 	void operator=(ExecutionEngine) = delete;
 
 	ReturnCode run(bytes const& _code, RuntimeData* _data, Env* _env);
-	ReturnCode run(std::unique_ptr<llvm::Module> module, RuntimeData* _data, Env* _env);
+	ReturnCode run(std::unique_ptr<llvm::Module> module, RuntimeData* _data, Env* _env, bytes const& _code);
 
 	bytes returnData;