diff --git a/src/languagecodes.h b/src/languagecodes.h
index 405144c..28364c4 100644
--- a/src/languagecodes.h
+++ b/src/languagecodes.h
@@ -4,6 +4,7 @@
 
 #include <optional>
 #include <unordered_map>
+#include <vector>
 
 using LanguageId = QString;