diff --git a/src/lib/ops_and_meta_predicates.pl b/src/lib/ops_and_meta_predicates.pl
index f84d0fd6..929165e3 100644
--- a/src/lib/ops_and_meta_predicates.pl
+++ b/src/lib/ops_and_meta_predicates.pl
@@ -15,7 +15,7 @@
 :- op(500, yfx, +).
 :- op(500, yfx, -).
 :- op(400, yfx, *).
-:- op(200, xfy, **).
+:- op(200, xfx, **).
 :- op(200, xfy, ^).
 :- op(500, yfx, /\).
 :- op(500, yfx, \/).