diff --git a/src/base/map_util.hh b/src/base/map_util.hh
index 1ab56293..d565f4e3 100644
--- a/src/base/map_util.hh
+++ b/src/base/map_util.hh
@@ -32,10 +32,10 @@
 
 #include <functional>
 #include <map>
+#include <optional>
 #include <type_traits>
 #include <vector>
 
-
 namespace lnav {
 namespace map {
 
diff --git a/src/file_format.hh b/src/file_format.hh
index 954f4568..32f4cafe 100644
--- a/src/file_format.hh
+++ b/src/file_format.hh
@@ -32,6 +32,8 @@
 #ifndef lnav_file_format_hh
 #define lnav_file_format_hh
 
+#include <optional>
+
 #include "fmt/format.h"
 #include "ghc/filesystem.hpp"