diff --git a/lib/isc/include/pk11/internal.h b/lib/isc/include/pk11/internal.h
index aa8907a..603712a 100644
--- a/lib/isc/include/pk11/internal.h
+++ b/lib/isc/include/pk11/internal.h
@@ -13,6 +13,8 @@
 #ifndef PK11_INTERNAL_H
 #define PK11_INTERNAL_H 1
 
+#include <pk11/pk11.h>
+
 /*! \file pk11/internal.h */
 
 ISC_LANG_BEGINDECLS