diff --git a/library/dialect/swi.yap b/library/dialect/swi.yap
index 8219e5fdf..fea5696be 100755
--- a/library/dialect/swi.yap
+++ b/library/dialect/swi.yap
@@ -24,6 +24,7 @@
 		   time_file/2,
 		   flag/3,
 		   require/1,
+		   normalize_space/2,
 		   current_flag/1
 		]).