diff --git a/src/Perl6/Actions.pm b/src/Perl6/Actions.pm
index 6028488583e..486d526a0ef 100644
--- a/src/Perl6/Actions.pm
+++ b/src/Perl6/Actions.pm
@@ -2051,8 +2051,11 @@ method prefix_circumfix_meta_operator:sym<reduce>($/) {
             PAST::Var.new( :name($opsub), :scope('package') ),
             PAST::Op.new(
                 :pasttype('callmethod'), :name('assuming'),
-                PAST::Op.new( :pirop('find_sub_not_null__Ps'), '&reduce' ),
-                PAST::Op.new( :pirop('find_sub_not_null__Ps'), $base_op )
+                PAST::Op.new( :pirop('find_sub_not_null__Ps'), '&reducewith' ),
+                PAST::Op.new( :pirop('find_sub_not_null__Ps'), $base_op ),
+                PAST::Val.new( :named('triangle'), :value($<triangle> ?? 1 !! 0) ),
+                PAST::Val.new( :named('chaining'), :value($<op><OPER><O><prec> eq 'm=') ),
+                PAST::Val.new( :named('right-assoc'), :value($<op><OPER><O><assoc> eq 'right') )
             )
         ));
         %*METAOPGEN{$opsub} := 1;
diff --git a/src/Perl6/Grammar.pm b/src/Perl6/Grammar.pm
index a1ca0529557..c0d633610df 100644
--- a/src/Perl6/Grammar.pm
+++ b/src/Perl6/Grammar.pm
@@ -1174,7 +1174,7 @@ regex prefix_circumfix_meta_operator:sym<reduce> {
     '['
     [
     || <op=.infixish> <?before ']'>
-#    || \\<op=.infixish> <?before ']'>
+    || $<triangle>=[\\]<op=.infixish> <?before ']'>
     || <!>
     ]
     ']'