diff --git a/libyul/backends/wasm/WasmDialect.cpp b/libyul/backends/wasm/WasmDialect.cpp
index fb230562e..8e0cba8f9 100644
--- a/libyul/backends/wasm/WasmDialect.cpp
+++ b/libyul/backends/wasm/WasmDialect.cpp
@@ -56,10 +56,16 @@ WasmDialect::WasmDialect():
 	addFunction("i64.eqz", 1, 1);
 	m_functions["i64.eqz"_yulstring].returns.front() = "i32"_yulstring;
 
+	addFunction("i64.clz", 1, 1);
+
 	addFunction("i64.store", 2, 0, false);
 	m_functions["i64.store"_yulstring].parameters.front() = "i32"_yulstring;
 	m_functions["i64.store"_yulstring].sideEffects.invalidatesStorage = false;
 
+	addFunction("i64.store8", 2, 0, false);
+	m_functions["i64.store8"_yulstring].parameters.front() = "i32"_yulstring;
+	m_functions["i64.store8"_yulstring].sideEffects.invalidatesStorage = false;
+
 	addFunction("i64.load", 1, 1, false);
 	m_functions["i64.load"_yulstring].parameters.front() = "i32"_yulstring;
 	m_functions["i64.load"_yulstring].sideEffects.invalidatesStorage = false;
diff --git a/test/tools/yulInterpreter/EWasmBuiltinInterpreter.cpp b/test/tools/yulInterpreter/EWasmBuiltinInterpreter.cpp
index 9a8c89262..a35a6f491 100644
--- a/test/tools/yulInterpreter/EWasmBuiltinInterpreter.cpp
+++ b/test/tools/yulInterpreter/EWasmBuiltinInterpreter.cpp
@@ -49,6 +49,21 @@ void copyZeroExtended(
 		_target[_targetOffset + i] = _sourceOffset + i < _source.size() ? _source[_sourceOffset + i] : 0;
 }
 
+/// Count leading zeros for uint64
+uint64_t clz(uint64_t _v)
+{
+	if (_v == 0)
+		return 64;
+
+	uint64_t r = 0;
+	while (!(_v & 0x8000000000000000))
+	{
+		r += 1;
+		_v = _v << 1;
+	}
+	return r;
+}
+
 }
 
 using u512 = boost::multiprecision::number<boost::multiprecision::cpp_int_backend<512, 256, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>>;
@@ -119,6 +134,8 @@ u256 EWasmBuiltinInterpreter::evalBuiltin(YulString _fun, vector<u256> const& _a
 		return arg[0] != arg[1] ? 1 : 0;
 	else if (_fun == "i64.eqz"_yulstring)
 		return arg[0] == 0 ? 1 : 0;
+	else if (_fun == "i64.clz"_yulstring)
+		return clz(arg[0]);
 	else if (_fun == "i64.lt_u"_yulstring)
 		return arg[0] < arg[1] ? 1 : 0;
 	else if (_fun == "i64.gt_u"_yulstring)
@@ -133,6 +150,12 @@ u256 EWasmBuiltinInterpreter::evalBuiltin(YulString _fun, vector<u256> const& _a
 		writeMemoryWord(arg[0], arg[1]);
 		return 0;
 	}
+	else if (_fun == "i64.store8"_yulstring)
+	{
+		accessMemory(arg[0], 1);
+		writeMemoryByte(arg[0], static_cast<uint8_t>(arg[1] & 0xff));
+		return 0;
+	}
 	else if (_fun == "i64.load"_yulstring)
 	{
 		accessMemory(arg[0], 8);
@@ -148,7 +171,7 @@ u256 EWasmBuiltinInterpreter::evalBuiltin(YulString _fun, vector<u256> const& _a
 		// TODO this does not read the address, but is consistent with
 		// EVM interpreter implementation.
 		// If we take the address into account, this needs to use readAddress.
-		writeU128(arg[0], m_state.balance);
+		writeU128(arg[1], m_state.balance);
 		return 0;
 	}
 	else if (_fun == "eth.getBlockHash"_yulstring)
@@ -368,6 +391,11 @@ void EWasmBuiltinInterpreter::writeMemoryWord(uint64_t _offset, uint64_t _value)
 		m_state.memory[_offset + i] = uint8_t((_value >> (i * 8)) & 0xff);
 }
 
+void EWasmBuiltinInterpreter::writeMemoryByte(uint64_t _offset, uint8_t _value)
+{
+	m_state.memory[_offset] = _value;
+}
+
 void EWasmBuiltinInterpreter::writeU256(uint64_t _offset, u256 _value, size_t _croppedTo)
 {
 	accessMemory(_offset, _croppedTo);
diff --git a/test/tools/yulInterpreter/EWasmBuiltinInterpreter.h b/test/tools/yulInterpreter/EWasmBuiltinInterpreter.h
index 8472b4a22..363c11f45 100644
--- a/test/tools/yulInterpreter/EWasmBuiltinInterpreter.h
+++ b/test/tools/yulInterpreter/EWasmBuiltinInterpreter.h
@@ -86,6 +86,9 @@ private:
 	/// Writes a word to memory (little-endian)
 	/// Does not adjust msize, use @a accessMemory for that
 	void writeMemoryWord(uint64_t _offset, uint64_t _value);
+	/// Writes a byte to memory
+	/// Does not adjust msize, use @a accessMemory for that
+	void writeMemoryByte(uint64_t _offset, uint8_t _value);
 
 	/// Helper for eth.* builtins. Writes to memory (big-endian) and always returns zero.
 	void writeU256(uint64_t _offset, dev::u256 _value, size_t _croppedTo = 32);