diff --git a/src/proto.h b/src/proto.h
index 78f814c..29f8238 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -211,6 +211,7 @@
 # include "spell.pro"
 # include "spellfile.pro"
 # include "spellsuggest.pro"
+# include "strings.pro"
 # include "syntax.pro"
 # include "tag.pro"
 # include "term.pro"