diff --git a/src/Episode3/DataIndexes.hh b/src/Episode3/DataIndexes.hh
index 8ea8d87d..3147d812 100644
--- a/src/Episode3/DataIndexes.hh
+++ b/src/Episode3/DataIndexes.hh
@@ -2,6 +2,7 @@
 
 #include <stdint.h>
 
+#include <array>
 #include <map>
 #include <memory>
 #include <phosg/Encoding.hh>