diff --git a/libevmjit/Compiler.cpp b/libevmjit/Compiler.cpp
index dd9224216..1ce63d8ec 100644
--- a/libevmjit/Compiler.cpp
+++ b/libevmjit/Compiler.cpp
@@ -456,14 +456,15 @@ void Compiler::compileBasicBlock(BasicBlock& _basicBlock, bytes const& _bytecode
 
 			// test for word >> (k * 8 + 7)
 			auto bitpos = m_builder.CreateAdd(k32x8, m_builder.getInt64(7), "bitpos");
-			auto bittester = m_builder.CreateShl(Constant::get(1), bitpos);
+			auto bitposEx = m_builder.CreateZExt(bitpos, Type::Word);
+			auto bittester = m_builder.CreateShl(Constant::get(1), bitposEx);
 			auto bitresult = m_builder.CreateAnd(word, bittester);
 			auto bittest = m_builder.CreateICmpUGT(bitresult, Constant::get(0));
 			// FIXME: The following does not work - LLVM bug, report!
 			//auto bitval = m_builder.CreateLShr(word, bitpos, "bitval");
 			//auto bittest = m_builder.CreateTrunc(bitval, Type::Bool, "bittest");
 
-			auto mask_ = m_builder.CreateShl(Constant::get(1), bitpos);
+			auto mask_ = m_builder.CreateShl(Constant::get(1), bitposEx);
 			auto mask = m_builder.CreateSub(mask_, Constant::get(1), "mask");
 
 			auto negmask = m_builder.CreateXor(mask, llvm::ConstantInt::getAllOnesValue(Type::Word), "negmask");