index 41fdde0..1aeae88 100644
--- a/src/patchelf.cc
+++ b/src/patchelf.cc
@@ -26,6 +26,7 @@
 #include <string>
 #include <unordered_map>
 #include <vector>
+#include <optional>
 
 #include <cassert>
 #include <cerrno>