diff --git a/basis/furnace/actions/actions.factor b/basis/furnace/actions/actions.factor
index aca03b9029..19491acfc3 100644
--- a/basis/furnace/actions/actions.factor
+++ b/basis/furnace/actions/actions.factor
@@ -28,10 +28,10 @@ TUPLE: action rest init authorize display validate submit ;
     action new-action ;
 
 : merge-forms ( form -- )
-    form get
-    [ [ errors>> ] bi@ push-all ]
-    [ [ values>> ] bi@ swap update ]
-    [ swap validation-failed>> >>validation-failed drop ]
+    [ form get ] dip
+    [ [ errors>> ] bi@ append! drop ]
+    [ [ values>> ] bi@ assoc-union! drop ]
+    [ validation-failed>> >>validation-failed drop ]
     2tri ;
 
 : set-nested-form ( form name -- )
diff --git a/basis/furnace/chloe-tags/chloe-tags.factor b/basis/furnace/chloe-tags/chloe-tags.factor
index 562fe5a614..8a08063595 100644
--- a/basis/furnace/chloe-tags/chloe-tags.factor
+++ b/basis/furnace/chloe-tags/chloe-tags.factor
@@ -136,7 +136,7 @@ CHLOE: form
     XML> body>> clone ;
 
 : add-tag-attrs ( attrs tag -- )
-    attrs>> swap update ;
+    attrs>> swap assoc-union! drop ;
 
 CHLOE: button
     button-tag-markup
diff --git a/basis/html/forms/forms.factor b/basis/html/forms/forms.factor
index 5cf318bcaf..cf959ba058 100644
--- a/basis/html/forms/forms.factor
+++ b/basis/html/forms/forms.factor
@@ -35,10 +35,10 @@ M: form clone
     [ [ value ] keep ] dip ; inline
 
 : from-object ( object -- )
-    [ values ] [ make-mirror ] bi* update ;
+    [ values ] [ make-mirror ] bi* assoc-union! drop ;
 
 : to-object ( destination names -- )
-    [ make-mirror ] [ values extract-keys ] bi* update ;
+    [ make-mirror ] [ values extract-keys ] bi* assoc-union! drop ;
 
 : with-each-value ( name quot -- )
     [ value ] dip '[
diff --git a/basis/regexp/negation/negation.factor b/basis/regexp/negation/negation.factor
index 8b0a2f6edf..802e211536 100644
--- a/basis/regexp/negation/negation.factor
+++ b/basis/regexp/negation/negation.factor
@@ -44,7 +44,7 @@ CONSTANT: fail-state -1
     unify-final-state renumber-states box-transitions 
     [ start-state>> ]
     [ final-states>> keys first ]
-    [ nfa-table get [ transitions>> ] bi@ swap update ] tri ;
+    [ nfa-table get [ transitions>> ] bi@ swap assoc-union! drop ] tri ;
 
 : ast>dfa ( parse-tree -- minimal-dfa )
     construct-nfa disambiguate construct-dfa minimize ;
diff --git a/basis/serialize/serialize.factor b/basis/serialize/serialize.factor
index 0840c778d7..10d68fee59 100644
--- a/basis/serialize/serialize.factor
+++ b/basis/serialize/serialize.factor
@@ -236,7 +236,7 @@ SYMBOL: deserialized
 : deserialize-hashtable ( -- hashtable )
     H{ } clone
     [ intern-object ]
-    [ (deserialize) update ]
+    [ (deserialize) assoc-union! drop ]
     [ ] tri ;
 
 : copy-seq-to-tuple ( seq tuple -- )
diff --git a/basis/xmode/catalog/catalog.factor b/basis/xmode/catalog/catalog.factor
index 40b8e2191c..5d0f7f0ea4 100644
--- a/basis/xmode/catalog/catalog.factor
+++ b/basis/xmode/catalog/catalog.factor
@@ -67,7 +67,7 @@ DEFER: finalize-rule-set
     [ resolve-delegate ] each-rule ;
 
 : ?update ( keyword-map/f keyword-map -- keyword-map )
-    over [ dupd update ] [ nip clone ] if ;
+    over [ assoc-union! ] [ nip clone ] if ;
 
 : import-keywords ( parent child -- )
     over [ [ keywords>> ] bi@ ?update ] dip (>>keywords) ;
diff --git a/basis/xmode/keyword-map/keyword-map-tests.factor b/basis/xmode/keyword-map/keyword-map-tests.factor
index b14bbd0f70..0e5c03fb57 100644
--- a/basis/xmode/keyword-map/keyword-map-tests.factor
+++ b/basis/xmode/keyword-map/keyword-map-tests.factor
@@ -8,7 +8,7 @@ f <keyword-map> dup "k" set
     { "int" KEYWORD1 }
     { "void" KEYWORD2 }
     { "size_t" KEYWORD3 }
-} update
+} assoc-union! drop
 
 [ 3 ] [ "k" get assoc-size ] unit-test
 [ KEYWORD1 ] [ "int" "k" get at ] unit-test
@@ -21,7 +21,7 @@ t <keyword-map> dup "k" set
     { "Foo" KEYWORD1 }
     { "bbar" KEYWORD2 }
     { "BAZ" KEYWORD3 }
-} update
+} assoc-union! drop
 
 [ KEYWORD1 ] [ "fOo" "k" get at ] unit-test
 
diff --git a/extra/id3/id3.factor b/extra/id3/id3.factor
index 6a14280e6e..9c25c2cb57 100644
--- a/extra/id3/id3.factor
+++ b/extra/id3/id3.factor
@@ -153,7 +153,7 @@ CONSTANT: id3v1+-length 227
     } cleave ;
 
 : merge-frames ( id3 assoc -- id3 )
-    [ dup frames>> ] dip update ;
+    [ dup frames>> ] dip assoc-union! drop ;
 
 : merge-id3v1 ( id3 -- id3 )
     dup id3v1>frames frames>assoc merge-frames ;
diff --git a/extra/multi-methods/multi-methods.factor b/extra/multi-methods/multi-methods.factor
index 6bed6d5f32..caf37dbadb 100644
--- a/extra/multi-methods/multi-methods.factor
+++ b/extra/multi-methods/multi-methods.factor
@@ -40,7 +40,7 @@ SYMBOL: total
     ] assoc-map ;
 
 : canonicalize-specializer-3 ( specializer -- specializer' )
-    [ total get object <array> dup <enum> ] dip update ;
+    [ total get object <array> <enum> ] dip assoc-union! seq>> ;
 
 : canonicalize-specializers ( methods -- methods' hooks )
     [