diff --git a/extra/smalltalk/parser/parser-tests.factor b/extra/smalltalk/parser/parser-tests.factor
index 5fd3d57857..7588dfba24 100644
--- a/extra/smalltalk/parser/parser-tests.factor
+++ b/extra/smalltalk/parser/parser-tests.factor
@@ -298,3 +298,5 @@ test         = <foreign parse-smalltalk LocalVariableDeclarationList>
 { } [ "class Foo []. Tests blah " parse-smalltalk drop ] unit-test
 
 { } [ "vocab:smalltalk/parser/test.st" ascii file-contents parse-smalltalk drop ] unit-test
+
+{ } [ "_abc_" parse-smalltalk drop ] unit-test
diff --git a/extra/smalltalk/parser/parser.factor b/extra/smalltalk/parser/parser.factor
index 6de20afc6d..892f2e4ad8 100644
--- a/extra/smalltalk/parser/parser.factor
+++ b/extra/smalltalk/parser/parser.factor
@@ -16,7 +16,7 @@ ERROR: bad-number str ;
 EBNF: parse-smalltalk
 
 Character = .
-WhitespaceCharacter = (" " | "\t" | "\n" | "\r" )
+WhitespaceCharacter = [ \t\n\r]
 DecimalDigit = [0-9]
 Letter = [A-Za-z]
 
@@ -27,7 +27,7 @@ OptionalWhiteSpace = (WhitespaceCharacter | Comment)*
 Whitespace = (WhitespaceCharacter | Comment)+
 
 LetterOrDigit = DecimalDigit | Letter
-Identifier = (Letter | "_"):h (LetterOrDigit | "_")*:t => [[ { h t } flatten >string ]]
+Identifier = (Letter | [_]):h (LetterOrDigit | [_])*:t => [[ { h t } flatten >string ]]
 Reference = Identifier => [[ ast-name boa ]]
 
 ConstantReference =   "nil" => [[ nil ]]