diff --git a/lib/utils/mu-html-to-text.cc b/lib/utils/mu-html-to-text.cc
index b6d97850..08f1f4dc 100644
--- a/lib/utils/mu-html-to-text.cc
+++ b/lib/utils/mu-html-to-text.cc
@@ -22,6 +22,7 @@
 #include "mu-regex.hh"
 
 #include <string>
+#include <array>
 #include <string_view>
 #include <algorithm>