diff --git a/trees/cb/cb-tests.factor b/trees/cb/cb-tests.factor
index 8b3ae46..d1fc611 100644
--- a/trees/cb/cb-tests.factor
+++ b/trees/cb/cb-tests.factor
@@ -1,13 +1,40 @@
 USING: assocs kernel tools.test trees trees.cb trees.cb.private trees.private ;
 IN: trees.cb.tests
 
-CONSTANT: 4tree CB{ { 0 0 } { 1 1 } { 2 2 } { 3 3 } }
+: 4tree ( -- tree )
+    CB{ { 0 0 } { 1 1 } { 2 2 } { 3 3 } } clone ;
 
 ! Insertion into an empty tree
 { CB{ { 0 0 } } } [
     0 0 <cb> [ set-at ] keep
 ] unit-test
 
+! Double inserts
+! single leaf
+{
+    CB{ { 0 0 } }
+} [
+    0 0 <cb> [ set-at ] keep
+    0 0 rot [ set-at ] keep
+] unit-test
+
+! left leaf
+{
+    CB{ { 0 0 } { 1 1 } }
+} [
+    CB{ { 0 0 } { 1 1 } }
+    0 0 rot [ set-at ] keep
+] unit-test
+
+! right leaf
+{
+    CB{ { 0 0 } { 1 1 } }
+} [
+    CB{ { 0 0 } { 1 1 } }
+    1 1 rot [ set-at ] keep
+] unit-test
+
+! Splits
 ! Insertion into a leaf-node resulting in splitting
 {
     CB{ { 0 0 } { 1 1 } }
@@ -15,3 +42,25 @@ CONSTANT: 4tree CB{ { 0 0 } { 1 1 } { 2 2 } { 3 3 } }
     0 0 <cb> [ set-at ] keep
     1 1 rot [ set-at ] keep
 ] unit-test
+
+! Splitting at the root
+{
+    CB{ { 0 0 } { 1 1 } { 2 2 } { 3 3 } { 4 4 } }
+} [
+    CB{ { 0 0 } { 1 1 } { 2 2 } { 3 3 } }
+    4 4 rot [ set-at ] keep
+] unit-test
+
+! Collision
+{
+    CB{ { B{ 110 } B{ 110 } } }
+} [
+    CB{ { f f } }
+    B{ 110 } dup rot [ set-at ] keep
+] unit-test
+
+! Colliding trees are still not equal
+{ f } [
+    CB{ { f f } }
+    CB{ { B{ 110 } B{ 110 } } } =
+] unit-test
diff --git a/trees/cb/cb.factor b/trees/cb/cb.factor
index 0e724f5..efba7c2 100644
--- a/trees/cb/cb.factor
+++ b/trees/cb/cb.factor
@@ -34,8 +34,8 @@ TUPLE: cb-node { byte# integer } { bits fixnum } left right ;
     swap >>bits
     swap >>byte# ; inline
 
-: <cb-node> ( byte# bits -- node )
-    cb-node new-node ;
+: <cb-node> ( bits byte# -- node )
+    swap cb-node new-node ;
 
 : key-side ( bits byte -- side )
     bitor 1 + -8 shift 0 = left right ? ;
@@ -67,12 +67,8 @@ TUPLE: cb-node { byte# integer } { bits fixnum } left right ;
     [
         [ -rot 2nth-unsafe byte-diff ] keep
     ] [
-        ! [ [ length ] bi@ = ] 2keep rot
-        ! [ 2drop 0 0 f ]
-        ! [
             [ min-length dup ] 2keep
             2nth0 byte-diff rot
-        ! ] if
     ] if* ;
 
 PRIVATE>
@@ -159,8 +155,8 @@ M: node cb-update
         current-key get >>key
         swap >>value f
     ] [
-        key>> key>bytes key-bytes get swap
-        bytes-diff swap <cb-node>
+        [ key-bytes get ] dip key>> key>bytes
+        bytes-diff <cb-node>
         attach-node t
     ] if ;