diff --git a/extra/modern/compiler/compiler.factor b/extra/modern/compiler/compiler.factor
index 3fc4d8e5f5..dee209e005 100644
--- a/extra/modern/compiler/compiler.factor
+++ b/extra/modern/compiler/compiler.factor
@@ -58,7 +58,7 @@ ARITY: \HOOK: 3
 ARITY: \IN: 1
 ARITY: \INSTANCE: 2
 ARITY: \MAIN: 1
-ARITY: \MATH: 1
+ARITY: \MATH: 2
 ARITY: \MIXIN: 1
 ARITY: \PRIMITIVE: 2
 ARITY: \QUALIFIED-WITH: 2
diff --git a/extra/modern/manifest/manifest.factor b/extra/modern/manifest/manifest.factor
index be6e502b59..86d14564d7 100644
--- a/extra/modern/manifest/manifest.factor
+++ b/extra/modern/manifest/manifest.factor
@@ -1,7 +1,8 @@
 ! Copyright (C) 2019 Doug Coleman.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: accessors arrays assocs combinators kernel modern
-sequences splitting.monotonic strings words ;
+USING: accessors arrays assocs combinators
+combinators.short-circuit kernel modern sequences
+splitting.monotonic strings words ;
 IN: modern.manifest
 
 TUPLE: syntax-forms
@@ -76,6 +77,7 @@ ERROR: key-exists val key assoc existing-value ;
         "defer" "DEFER" add-ucolon-form
         "error" "ERROR" add-ucolon-form
         "exclude" "EXCLUDE" add-ucolon-form
+        "forget" "FORGET" add-ucolon-form
         "generic#" "GENERIC#" add-ucolon-form
         "generic" "GENERIC" add-ucolon-form
         "hints" "HINTS" add-ucolon-form
@@ -166,6 +168,7 @@ ERROR: key-exists val key assoc existing-value ;
         2 "C" add-ucolon-arity
         2 "CONSTANT" add-ucolon-arity
         1 "DEFER" add-ucolon-arity
+        1 "FORGET" add-ucolon-arity
         3 "GENERIC#" add-ucolon-arity
         2 "GENERIC" add-ucolon-arity
         3 "HOOK" add-ucolon-arity