diff --git a/library/yap2swi/yap2swi.c b/library/yap2swi/yap2swi.c
index 69209f39a..eac753789 100644
--- a/library/yap2swi/yap2swi.c
+++ b/library/yap2swi/yap2swi.c
@@ -24,6 +24,8 @@
 #include	<math.h>
 #endif
 
+#define PL_KERNEL 1
+
 #include	<SWI-Stream.h>
 #include	<SWI-Prolog.h>