diff --git a/lib/IntrinsicReplacement.cpp b/lib/IntrinsicReplacement.cpp
index 1b9c400..60bc10c 100644
--- a/lib/IntrinsicReplacement.cpp
+++ b/lib/IntrinsicReplacement.cpp
@@ -38,8 +38,13 @@ void IntrinsicReplacement::mutate(llvm::Instruction *instruction) {
   assert(instruction);
   assert(canMutate(instruction));
   auto intrinsic = llvm::cast<llvm::IntrinsicInst>(instruction);
+#if LLVM_VERSION_MAJOR >= 20
+  auto replacement = llvm::Intrinsic::getOrInsertDeclaration(
+      instruction->getModule(), to, { intrinsic->getFunctionType()->getParamType(0) });
+#else
   auto replacement = llvm::Intrinsic::getDeclaration(
       instruction->getModule(), to, { intrinsic->getFunctionType()->getParamType(0) });
+#endif
 
   std::vector<llvm::Value *> arguments;
   for (auto &arg : intrinsic->args()) {
diff --git a/lib/NegateXORReplacement.cpp b/lib/NegateXORReplacement.cpp
index bce0d1d..d750daa 100644
--- a/lib/NegateXORReplacement.cpp
+++ b/lib/NegateXORReplacement.cpp
@@ -46,7 +46,13 @@ void NegateXORReplacement::mutate(llvm::Instruction *instruction) {
   /// entry:
   /// %not = xor i1 false, true
   /// %xor = xor i1 true, %not
+
+#if LLVM_VERSION_MAJOR >= 20
+  auto position = llvm::BasicBlock::iterator(instruction);
+#else
+  auto position = instruction;
+#endif
   auto rhs = instruction->getOperand(1);
-  auto notInstruction = llvm::BinaryOperator::CreateNot(rhs, "not", instruction);
+  auto notInstruction = llvm::BinaryOperator::CreateNot(rhs, "not", position);
   instruction->setOperand(1, notInstruction);
 }