diff --git a/lib/kbsemi.gi b/lib/kbsemi.gi
index 5b1f508ccce..16ad3c489d8 100644
--- a/lib/kbsemi.gi
+++ b/lib/kbsemi.gi
@@ -182,6 +182,9 @@ DeclareRepresentation("IsKnuthBendixRewritingSystemRep",
 ##  refers to one of the rules. A pair corresponds to a pair
 ##  of rules where confluence was not yet checked (according to
 ##  the Knuth Bendix algorithm).
+##  Pairs might also be given in the form of a 3-entry list
+##  ['A',x,l] to denote all pairs of the form [x,y] for y in l,
+##  respectively ['B',l,y] for pairs [x,y[] with x in l.
 ##
 ##  Note that at this stage the kb rws obtained might not be reduced
 ##  (the same relation might even appear several times).
@@ -767,6 +770,22 @@ function ( rws )
        " rules" );
 end);
 
+# We store compressed data -- expand, (and also delete old stuff)
+BindGlobal("KBRWSUnpackPairsAt",function(kbrws,p)
+local i,a;
+  i:=kbrws!.pairs2check[p];
+  if IsChar(i[1]) then
+    # We store compressed data -- expand, (and also delete old stuff)
+    if i[1]='A' then
+      a:=List(i[3],x->[i[2],x]);
+    elif i[1]='B' then
+      a:=List(i[2],x->[x,i[3]]);
+    else Error("kind"); fi;
+    kbrws!.pairs2check:=Concatenation(a,kbrws!.pairs2check{[p+1..Length(kbrws!.pairs2check)]});
+    p:=1;
+  fi;
+  return p;
+end);
 
 
 
@@ -776,7 +795,15 @@ end);
 BindGlobal("KBOverlaps",function(ui,vi,kbrws,p)
 local u,v,m,k,a,c,lsu,lsv,lu,eq,i,j;
 
+  # work around copied code in kan package
+  if IsChar(ui) then # must unpack
+    p:=KBRWSUnpackPairsAt(kbrws,p);
+    vi:=kbrws!.pairs2check[p];
+    ui:=vi[1];vi:=vi[2];
+  fi;
+
   u:=kbrws!.tzrules[ui]; v:=kbrws!.tzrules[vi];
+
   lsu:=u[1];
   lu:=Length(lsu);
   lsv:=v[1];
@@ -860,15 +887,7 @@ local   pn,lp,rl,p,i,a;
     i:=kbrws!.pairs2check[p];
     if IsChar(i[1]) then
       # We store compressed data -- expand, (and also delete old stuff)
-      if i[1]='A' then
-        a:=List(i[3],x->[i[2],x]);
-      elif i[1]='B' then
-        a:=List(i[2],x->[x,i[3]]);
-      else Error("kind"); fi;
-      kbrws!.pairs2check:=Concatenation(a,kbrws!.pairs2check{[p+1..Length(kbrws!.pairs2check)]});
-      p:=1;
-      i:=kbrws!.pairs2check[p];
-      lp:=Length(kbrws!.pairs2check);
+      p:=KBRWSUnpackPairsAt(kbrws,p);
     fi;
 
     p:=KBOverlaps(i[1],i[2],kbrws,p)+1;