1 files changed, 1 insertions, 0 deletions
diff --git a/src/pch.h b/src/pch.h
index e86c0da6..1d8df43a 100644
--- a/src/pch.h
+++ b/src/pch.h
@@ -13,6 +13,7 @@
 #include <list>
 #include <map>
 #include <memory>
+#include <optional>
 #include <regex>
 #include <set>
 #include <sstream>