diff --git a/src/lib/icu/Converter.hxx b/src/lib/icu/Converter.hxx
index f7e3eabe3..ca4eeca48 100644
--- a/src/lib/icu/Converter.hxx
+++ b/src/lib/icu/Converter.hxx
@@ -34,6 +34,7 @@
 #ifdef HAVE_ICU_CONVERTER
 
 #include <memory>
+#include <string_view>
 
 #ifdef HAVE_ICU
 struct UConverter;