diff --git a/core/bootstrap/primitives.factor b/core/bootstrap/primitives.factor
index d5cedaf7b3..c9329a2c9f 100755
--- a/core/bootstrap/primitives.factor
+++ b/core/bootstrap/primitives.factor
@@ -5,7 +5,7 @@ USING: alien arrays byte-arrays generic hashtables
 hashtables.private io kernel math namespaces parser sequences
 strings vectors words quotations assocs layouts classes tuples
 kernel.private vocabs vocabs.loader source-files definitions
-slots classes.union words.private ;
+slots classes.union words.private compiler.units ;
 
 ! Some very tricky code creating a bootstrap embryo in the
 ! host image.
diff --git a/core/bootstrap/stage2.factor b/core/bootstrap/stage2.factor
index 468f9250cc..2bcd4ce82f 100755
--- a/core/bootstrap/stage2.factor
+++ b/core/bootstrap/stage2.factor
@@ -80,5 +80,5 @@ IN: bootstrap.stage2
         "output-image" get resource-path save-image-and-exit
     ] if
 ] [
-    error-hook get call "listener" vocab-main execute
+    error. :c "listener" vocab-main execute
 ] recover
diff --git a/core/classes/mixin/mixin.factor b/core/classes/mixin/mixin.factor
index 847cce30bf..f9b987eb78 100755
--- a/core/classes/mixin/mixin.factor
+++ b/core/classes/mixin/mixin.factor
@@ -68,7 +68,7 @@ M: mixin-instance definer drop \ INSTANCE: f ;
 
 M: mixin-instance definition drop f ;
 
-M: mixin-instance forget
+M: mixin-instance forget*
     dup mixin-instance-class
     swap mixin-instance-mixin dup mixin-class?
     [ remove-mixin-instance ] [ 2drop ] if ;
diff --git a/core/compiler/units/units.factor b/core/compiler/units/units.factor
index 93994012e3..af56f1796b 100755
--- a/core/compiler/units/units.factor
+++ b/core/compiler/units/units.factor
@@ -56,16 +56,17 @@ GENERIC: definitions-changed ( assoc obj -- )
     definition-observers get
     [ definitions-changed ] curry* each ;
 
-: changed-vocabs ( -- assoc )
-    changed-words get
+: changed-vocabs ( assoc -- vocabs )
+    [ drop word? ] assoc-subset
     [ drop word-vocabulary dup [ vocab ] when dup ] assoc-map ;
 
 : changed-definitions ( -- assoc )
     H{ } clone
+    dup forgotten-definitions get update
     dup new-definitions get first update
     dup new-definitions get second update
     dup changed-words get update
-    dup changed-vocabs update ;
+    dup dup changed-vocabs update ;
 
 : finish-compilation-unit ( -- )
     changed-words get keys recompile-hook get call
@@ -74,6 +75,7 @@ GENERIC: definitions-changed ( assoc obj -- )
 : with-compilation-unit ( quot -- )
     [
         H{ } clone changed-words set
+        H{ } clone forgotten-definitions set
         <definitions> new-definitions set
         <definitions> old-definitions set
         [ finish-compilation-unit ]
diff --git a/core/cpu/x86/bootstrap.factor b/core/cpu/x86/bootstrap.factor
index 7b609ab1c9..fd5a4703a8 100755
--- a/core/cpu/x86/bootstrap.factor
+++ b/core/cpu/x86/bootstrap.factor
@@ -2,7 +2,7 @@
 ! See http://factorcode.org/license.txt for BSD license.
 USING: bootstrap.image.private kernel namespaces system
 cpu.x86.assembler layouts compiler.units math generator.fixup
-compiler.constants ;
+compiler.constants vocabs ;
 IN: bootstrap.x86
 
 big-endian off
diff --git a/core/debugger/debugger.factor b/core/debugger/debugger.factor
index 1d5185deb1..77c6da38e9 100755
--- a/core/debugger/debugger.factor
+++ b/core/debugger/debugger.factor
@@ -230,5 +230,5 @@ M: undefined summary
 
 M: no-compilation-unit error.
     "Attempting to define " write
-    no-compilation-unit-word pprint
+    no-compilation-unit-definition pprint
     " outside of a compilation unit" print ;
diff --git a/core/definitions/definitions.factor b/core/definitions/definitions.factor
index 6508d30216..ad261df7d4 100755
--- a/core/definitions/definitions.factor
+++ b/core/definitions/definitions.factor
@@ -3,15 +3,29 @@
 IN: definitions
 USING: kernel sequences namespaces assocs graphs ;
 
+TUPLE: no-compilation-unit definition ;
+
+: no-compilation-unit ( definition -- * )
+    \ no-compilation-unit construct-boa throw ;
+
 GENERIC: where ( defspec -- loc )
 
 M: object where drop f ;
 
 GENERIC: set-where ( loc defspec -- )
 
-GENERIC: forget ( defspec -- )
+GENERIC: forget* ( defspec -- )
 
-M: object forget drop ;
+M: object forget* drop ;
+
+SYMBOL: forgotten-definitions
+
+: forgotten-definition ( defspec -- )
+    dup forgotten-definitions get
+    [ no-compilation-unit ] unless*
+    set-at ;
+
+: forget ( defspec -- ) dup forgotten-definition forget* ;
 
 : forget-all ( definitions -- ) [ forget ] each ;
 
diff --git a/core/generic/generic.factor b/core/generic/generic.factor
index d57c4500e2..7c56d43b72 100755
--- a/core/generic/generic.factor
+++ b/core/generic/generic.factor
@@ -85,7 +85,7 @@ M: method-spec definer drop \ M: \ ; ;
 
 M: method-spec definition first2 method method-def ;
 
-M: method-spec forget first2 [ delete-at ] with-methods ;
+M: method-spec forget* first2 [ delete-at ] with-methods ;
 
 : implementors* ( classes -- words )
     all-words [
@@ -99,7 +99,7 @@ M: method-spec forget first2 [ delete-at ] with-methods ;
 : forget-methods ( class -- )
     [ implementors ] keep [ swap 2array ] curry map forget-all ;
 
-M: class forget ( class -- )
+M: class forget* ( class -- )
     dup forget-methods
     dup uncache-class
     forget-word ;
diff --git a/core/source-files/source-files.factor b/core/source-files/source-files.factor
index 6f50502f54..80538e2cf5 100755
--- a/core/source-files/source-files.factor
+++ b/core/source-files/source-files.factor
@@ -73,7 +73,7 @@ uses definitions ;
 
 M: pathname where pathname-string 1 2array ;
 
-M: pathname forget
+M: pathname forget*
     pathname-string
     dup source-file
     dup unxref-source
diff --git a/core/vocabs/vocabs.factor b/core/vocabs/vocabs.factor
index c47798e414..daa5658c07 100755
--- a/core/vocabs/vocabs.factor
+++ b/core/vocabs/vocabs.factor
@@ -105,4 +105,4 @@ UNION: vocab-spec vocab vocab-link ;
     dup vocab-words values forget-all
     vocab-name dictionary get delete-at ;
 
-M: vocab-spec forget forget-vocab ;
+M: vocab-spec forget* forget-vocab ;
diff --git a/core/words/words.factor b/core/words/words.factor
index b36e5cba81..e05fc0009a 100755
--- a/core/words/words.factor
+++ b/core/words/words.factor
@@ -92,11 +92,6 @@ M: word redefined* ( word -- )
 
 SYMBOL: changed-words
 
-TUPLE: no-compilation-unit word ;
-
-: no-compilation-unit ( word -- * )
-    \ no-compilation-unit construct-boa throw ;
-
 : changed-word ( word -- )
     dup changed-words get
     [ no-compilation-unit ] unless*
@@ -194,7 +189,7 @@ M: word (forget-word)
     dup delete-xref
     (forget-word) ;
 
-M: word forget forget-word ;
+M: word forget* forget-word ;
 
 M: word hashcode*
     nip 1 slot { fixnum } declare ;
diff --git a/extra/help/definitions/definitions.factor b/extra/help/definitions/definitions.factor
index 559acf3919..4d942ae3a9 100755
--- a/extra/help/definitions/definitions.factor
+++ b/extra/help/definitions/definitions.factor
@@ -12,7 +12,7 @@ M: link where link-name article article-loc ;
 
 M: link set-where link-name article set-article-loc ;
 
-M: link forget link-name remove-article ;
+M: link forget* link-name remove-article ;
 
 M: link definition article-content ;
 
@@ -34,4 +34,4 @@ M: word-link synopsis*
     link-name dup pprint-word
     stack-effect. ;
 
-M: word-link forget link-name remove-word-help ;
+M: word-link forget* link-name remove-word-help ;
diff --git a/extra/sudoku/deploy.factor b/extra/sudoku/deploy.factor
new file mode 100755
index 0000000000..de60bed20b
--- /dev/null
+++ b/extra/sudoku/deploy.factor
@@ -0,0 +1,13 @@
+USING: tools.deploy.config ;
+H{
+    { deploy-reflection 2 }
+    { deploy-word-props? f }
+    { deploy-compiler? t }
+    { deploy-math? f }
+    { deploy-c-types? f }
+    { deploy-io 2 }
+    { deploy-ui? f }
+    { deploy-name "Sudoku" }
+    { "stop-after-last-window?" t }
+    { deploy-word-defs? f }
+}