diff --git a/sycl/source/detail/event_impl.hpp b/sycl/source/detail/event_impl.hpp
index f9ea6167943ba..1a6bf26dc9931 100644
--- a/sycl/source/detail/event_impl.hpp
+++ b/sycl/source/detail/event_impl.hpp
@@ -19,6 +19,7 @@
 #include <atomic>
 #include <cassert>
 #include <condition_variable>
+#include <optional>
 
 __SYCL_INLINE_NAMESPACE(cl) {
 namespace sycl {