diff --git a/lib/sl/slc-gram.y b/lib/sl/slc-gram.y
index 6e76ff379..55d6b9cb5 100644
--- a/lib/sl/slc-gram.y
+++ b/lib/sl/slc-gram.y
@@ -40,6 +40,7 @@
 #include <limits.h>
 #include <getarg.h>
 #include <vers.h>
+#include <roken.h>
 
 #include "slc.h"
 extern FILE *yyin;