diff --git a/llvm_passes/HipEmitLoweredNames.cpp b/llvm_passes/HipEmitLoweredNames.cpp
index 47c05ffc9..3c74942b7 100644
--- a/llvm_passes/HipEmitLoweredNames.cpp
+++ b/llvm_passes/HipEmitLoweredNames.cpp
@@ -34,6 +34,7 @@
 #include "llvm/Support/CommandLine.h"
 
 #include <fstream>
+#include <optional>
 
 #define PASS_NAME "emit-lowered-names"
 #define DEBUG_TYPE PASS_NAME