diff --git a/gap/classes.gi b/gap/classes.gi
index 8712731..48eaf15 100644
--- a/gap/classes.gi
+++ b/gap/classes.gi
@@ -39,7 +39,7 @@ InstallTrueMethod( IsExtraLoop, IsAssociative and IsLoop );
 ##  Returns true if <Q> is commutative.
 
 InstallMethod( IsCommutative, "for quasigroup",
-    [ IsQuasigroup ],
+    [ IsQuasigroup ], 20, # Need to beat GAP's library methods
 function( Q )
     return LeftSection( Q ) = RightSection( Q );
 end );