diff --git a/core/classes/classes.factor b/core/classes/classes.factor
index 096c620c28..ba5b43dc80 100755
--- a/core/classes/classes.factor
+++ b/core/classes/classes.factor
@@ -76,8 +76,8 @@ M: word reset-class drop ;
         tri
     ] { } make ;
 
-: class-usages ( class -- assoc )
-    [ update-map get at ] closure ;
+: class-usages ( class -- seq )
+    [ update-map get at ] closure keys ;
 
 <PRIVATE
 
@@ -116,13 +116,11 @@ GENERIC: update-class ( class -- )
 
 M: class update-class drop ;
 
-GENERIC: update-methods ( class assoc -- )
+GENERIC: update-methods ( class seq -- )
 
 : update-classes ( class -- )
     dup class-usages
-    [ nip keys [ update-class ] each ]
-    [ update-methods ]
-    2bi ;
+    [ nip [ update-class ] each ] [ update-methods ] 2bi ;
 
 : define-class ( word superclass members participants metaclass -- )
     #! If it was already a class, update methods after.
diff --git a/core/classes/mixin/mixin.factor b/core/classes/mixin/mixin.factor
index e70e649805..a2debe55a1 100755
--- a/core/classes/mixin/mixin.factor
+++ b/core/classes/mixin/mixin.factor
@@ -39,7 +39,7 @@ TUPLE: check-mixin-class mixin ;
 
 : update-classes/new ( mixin -- )
     class-usages
-    [ keys [ update-class ] each ]
+    [ [ update-class ] each ]
     [ implementors [ make-generic ] each ] bi ;
 
 : add-mixin-instance ( class mixin -- )
diff --git a/core/classes/tuple/tuple-tests.factor b/core/classes/tuple/tuple-tests.factor
index dc99734ce5..604914bd5c 100755
--- a/core/classes/tuple/tuple-tests.factor
+++ b/core/classes/tuple/tuple-tests.factor
@@ -109,6 +109,7 @@ TUPLE: yo-momma ;
 [
     [ t ] [ \ yo-momma class? ] unit-test
     [ ] [ \ yo-momma forget ] unit-test
+    [ ] [ \ <yo-momma> forget ] unit-test
     [ f ] [ \ yo-momma update-map get values memq? ] unit-test
 
     [ f ] [ \ yo-momma crossref get at ] unit-test
@@ -552,11 +553,11 @@ TUPLE: subclass-forget-test-3 < subclass-forget-test-2 ;
 
 [ ] [ "IN: classes.tuple.tests FORGET: subclass-forget-test" eval ] unit-test
 
-[ H{ { subclass-forget-test-2 subclass-forget-test-2 } } ]
+[ { subclass-forget-test-2 } ]
 [ subclass-forget-test-2 class-usages ]
 unit-test
 
-[ H{ { subclass-forget-test-3 subclass-forget-test-3 } } ]
+[ { subclass-forget-test-3 } ]
 [ subclass-forget-test-3 class-usages ]
 unit-test
 
@@ -565,3 +566,32 @@ unit-test
 [ subclass-forget-test-3 new ] must-fail
 
 [ "IN: classes.tuple.tests TUPLE: subclass-forget-test-4 < subclass-forget-test-2 ;" eval ] must-fail
+
+! More
+DEFER: subclass-reset-test
+DEFER: subclass-reset-test-1
+DEFER: subclass-reset-test-2
+DEFER: subclass-reset-test-3
+
+GENERIC: break-me ( obj -- )
+
+[ ] [ [ { integer break-me } forget ] with-compilation-unit ] unit-test
+
+[ ] [ "IN: classes.tuple.tests TUPLE: subclass-reset-test ;" <string-reader> "subclass-reset-test" parse-stream drop ] unit-test
+[ ] [ "IN: classes.tuple.tests TUPLE: subclass-reset-test-1 < subclass-reset-test ;" eval ] unit-test
+[ ] [ "IN: classes.tuple.tests TUPLE: subclass-reset-test-2 < subclass-reset-test ;" eval ] unit-test
+[ ] [ "IN: classes.tuple.tests TUPLE: subclass-reset-test-3 < subclass-reset-test-2 ;" eval ] unit-test
+
+[ ] [ "IN: classes.tuple.tests USE: kernel M: subclass-reset-test-1 break-me drop ;" eval ] unit-test
+
+[ ] [ "IN: classes.tuple.tests : subclass-reset-test ;" <string-reader> "subclass-reset-test" parse-stream drop ] unit-test
+
+[ f ] [ subclass-reset-test-1 tuple-class? ] unit-test
+[ f ] [ subclass-reset-test-2 tuple-class? ] unit-test
+[ subclass-forget-test-3 new ] must-fail
+
+[ t ] [ \ break-me "methods" word-prop assoc-empty? ] unit-test
+
+[ ] [ "IN: classes.tuple.tests USE: math USE: kernel M: integer break-me drop ;" eval ] unit-test
+
+[ f ] [ \ break-me "methods" word-prop assoc-empty? ] unit-test
diff --git a/core/classes/tuple/tuple.factor b/core/classes/tuple/tuple.factor
index 0b54d7d69f..5ba0b7e69c 100755
--- a/core/classes/tuple/tuple.factor
+++ b/core/classes/tuple/tuple.factor
@@ -166,7 +166,7 @@ M: tuple-class update-class
     3tri ;
 
 : subclasses ( class -- classes )
-    class-usages keys [ tuple-class? ] filter ;
+    class-usages [ tuple-class? ] filter ;
 
 : each-subclass ( class quot -- )
     >r subclasses r> each ; inline
diff --git a/core/generator/generator.factor b/core/generator/generator.factor
index 7e64935e07..241858c95b 100755
--- a/core/generator/generator.factor
+++ b/core/generator/generator.factor
@@ -72,10 +72,12 @@ GENERIC: generate-node ( node -- next )
 
 : word-dataflow ( word -- effect dataflow )
     [
-        dup "cannot-infer" word-prop [ cannot-infer-effect ] when
-        dup "no-compile" word-prop [ cannot-infer-effect ] when
-        dup specialized-def over dup 2array 1array infer-quot
-        finish-word
+        [
+            dup "cannot-infer" word-prop [ cannot-infer-effect ] when
+            dup "no-compile" word-prop [ cannot-infer-effect ] when
+            dup specialized-def over dup 2array 1array infer-quot
+            finish-word
+        ] maybe-cannot-infer
     ] with-infer ;
 
 : intrinsics ( #call -- quot )
diff --git a/core/generic/generic.factor b/core/generic/generic.factor
index 965c9d8ad8..7bc4c2bb54 100755
--- a/core/generic/generic.factor
+++ b/core/generic/generic.factor
@@ -157,31 +157,31 @@ GENERIC: implementors ( class/classes -- seq )
 M: class implementors
     all-words [ "methods" word-prop key? ] with filter ;
 
-M: assoc implementors
+M: sequence implementors
     all-words [
          "methods" word-prop keys
-        swap [ key? ] curry contains?
+        swap [ memq? ] curry contains?
     ] with filter ;
 
 : forget-methods ( class -- )
     [ implementors ] [ [ swap 2array ] curry ] bi map forget-all ;
 
-M: class forget* ( class -- )
-    [
-        class-usages [
-            drop
+: forget-class ( class -- )
+    class-usages [
+        {
+            [ "predicate" word-prop [ forget ] each ]
             [ forget-methods ]
             [ update-map- ]
             [ reset-class ]
-            tri
-        ] assoc-each
-    ]
-    [ call-next-method ] bi ;
+        } cleave
+    ] each ;
 
-M: assoc update-methods ( class assoc -- )
+M: class forget* ( class -- )
+    [ forget-class ] [ call-next-method ] bi ;
+
+M: sequence update-methods ( class seq -- )
     implementors [
-        [ update-generic ]
-        [ make-generic drop ] 2bi
+        [ update-generic ] [ make-generic drop ] 2bi
     ] with each ;
 
 : define-generic ( word combination -- )
diff --git a/core/inference/backend/backend.factor b/core/inference/backend/backend.factor
index de5ca6d5e6..8966a38496 100755
--- a/core/inference/backend/backend.factor
+++ b/core/inference/backend/backend.factor
@@ -421,6 +421,9 @@ TUPLE: missing-effect word ;
     [ "inferred-effect" set-word-prop ]
     2tri ;
 
+: maybe-cannot-infer ( word quot -- )
+    [ ] [ t "cannot-infer" set-word-prop ] cleanup ; inline
+
 : infer-word ( word -- effect )
     [
         [
@@ -431,7 +434,7 @@ TUPLE: missing-effect word ;
             finish-word
             current-effect
         ] with-scope
-    ] [ ] [ t "cannot-infer" set-word-prop ] cleanup ;
+    ] maybe-cannot-infer ;
 
 : custom-infer ( word -- )
     #! Customized inference behavior
diff --git a/core/parser/parser.factor b/core/parser/parser.factor
index 92bfc3f3a9..129d5ef2ee 100755
--- a/core/parser/parser.factor
+++ b/core/parser/parser.factor
@@ -539,8 +539,7 @@ SYMBOL: interactive-vocabs
 
 : reset-removed-classes ( -- )
     removed-classes
-    filter-moved [ class? ] filter
-    [ [ forget-methods ] [ reset-class ] bi ] each ;
+    filter-moved [ class? ] filter [ forget-class ] each ;
 
 : fix-class-words ( -- )
     #! If a class word had a compound definition which was