diff --git a/library/dialect/swi.yap b/library/dialect/swi.yap
index f52cf1610..ba0bbe4fe 100755
--- a/library/dialect/swi.yap
+++ b/library/dialect/swi.yap
@@ -6,7 +6,6 @@
 :- module(system, [concat_atom/2,
 		   concat_atom/3,
 		   setenv/2,
-		   is_absolute_file_name/1,
 		   read_clause/1,
 		   string/1,
 		   chdir/1,
@@ -219,7 +218,6 @@ goal_expansion(delete_directory(A), delete_directory(A)) :- swi_io.
 goal_expansion(make_directory(A), make_directory(A)) :- swi_io.
 goal_expansion(same_file(A,B),system:swi_same_file(A,B)) :- swi_io.
 goal_expansion(rename_file(A,B),system:swi_rename_file(A,B)) :- swi_io.
-goal_expansion(is_absolute_file_name(A), is_absolute_file_name(A)) :- swi_io.
 goal_expansion(file_base_name(A,B),system:swi_file_base_name(A,B)) :- swi_io.
 goal_expansion(file_directory_name(A,B),system:swi_file_directory_name(A,B)) :- swi_io.
 goal_expansion('$mark_executable'(A), system:'swi_is_absolute_file_name'(A)) :- swi_io.
@@ -296,9 +294,6 @@ concat_atom(List, New) :-
 
 setenv(X,Y) :- unix(putenv(X,Y)).
 
-is_absolute_file_name(X) :-
-	absolute_file_name(X,X).
-
 read_clause(X,Y) :-
 	read_term(X,Y,[singetons(warning)]).