diff --git a/extra/lisp/lisp.factor b/extra/lisp/lisp.factor
index 52faf59c17..8582021d6d 100644
--- a/extra/lisp/lisp.factor
+++ b/extra/lisp/lisp.factor
@@ -26,14 +26,14 @@ DEFER: funcall
   unclip convert-form swap convert-body [ , % funcall ] bake ;
   
 <PRIVATE  
-: localize-body ( vars body -- newbody )  
-  [ dup lisp-symbol? [ tuck name>> swap member? [ name>> make-local ] [ ] if ]
-                     [ dup s-exp? [ body>> localize-body <s-exp> ] [ nip ] if ] if
-                   ] with map ;
+: localize-body ( assoc body -- assoc newbody )  
+  [ dup lisp-symbol? [ over dupd [ name>> ] dip at swap or ]
+                     [ dup s-exp? [ body>> localize-body <s-exp> ] when ] if
+                   ] map ;
   
 : localize-lambda ( body vars -- newbody newvars )
-  dup make-locals dup push-locals [ swap localize-body <s-exp> convert-form ] dipd
-  pop-locals swap ;
+  make-locals dup push-locals swap
+  [ swap localize-body <s-exp> convert-form swap pop-locals ] dip swap ;
   
 PRIVATE>
                    
diff --git a/extra/lisp/parser/parser-tests.factor b/extra/lisp/parser/parser-tests.factor
index 9e6b54ab0c..98a6d2a6ba 100644
--- a/extra/lisp/parser/parser-tests.factor
+++ b/extra/lisp/parser/parser-tests.factor
@@ -8,6 +8,14 @@ IN: lisp.parser.tests
   "1234" "atom" \ lisp-expr rule parse parse-result-ast
 ] unit-test
 
+{ -42  }  [
+  "-42" "atom" \ lisp-expr rule parse parse-result-ast
+] unit-test
+
+{ 37/52 } [
+  "37/52" "atom" \ lisp-expr rule parse parse-result-ast
+] unit-test
+
 { 123.98 } [
   "123.98" "atom" \ lisp-expr rule parse parse-result-ast
 ] unit-test
diff --git a/extra/lisp/parser/parser.factor b/extra/lisp/parser/parser.factor
index 65ad01aa6f..32886f9367 100644
--- a/extra/lisp/parser/parser.factor
+++ b/extra/lisp/parser/parser.factor
@@ -1,7 +1,7 @@
 ! Copyright (C) 2008 James Cash
 ! See http://factorcode.org/license.txt for BSD license.
 USING: kernel peg.ebnf peg.expr math.parser sequences arrays strings
-combinators.lib ;
+combinators.lib math ;
 
 IN: lisp.parser
 
@@ -18,9 +18,11 @@ RPAREN       = ")"
 dquote       = '"'
 squote       = "'"
 digit        = [0-9]
-integer      = (digit)+                            => [[ string>number ]]
-float        = (digit)+ "." (digit)*               => [[ first3 >string [ >string ] dipd 3append string>number ]]
+integer      = ("-")? (digit)+                           => [[ first2 append string>number ]]
+float        = integer "." (digit)*                      => [[ first3 >string [ number>string ] dipd 3append string>number ]]
+rational     = integer "/" (digit)+                      => [[ first3 nip string>number / ]]
 number       = float
+              | rational
               | integer
 id-specials  = "!" | "$" | "%" | "&" | "*" | "/" | ":" | "<"
               | " =" | ">" | "?" | "^" | "_" | "~" | "+" | "-" | "." | "@"