diff --git a/src/prolog/toplevel.pl b/src/prolog/toplevel.pl
index e7eb3b7a..dc58c386 100644
--- a/src/prolog/toplevel.pl
+++ b/src/prolog/toplevel.pl
@@ -145,7 +145,7 @@
     ).
 
 '$read_input'(ThreadedGoals, NewVarList) :-
-    '$get_single_char'(C),
+    get_single_char(C),
     (  C == w ->
        nl,
        write('   '),