diff --git a/extra/smalltalk/parser/parser.factor b/extra/smalltalk/parser/parser.factor
index c7cafe94dd..6de20afc6d 100644
--- a/extra/smalltalk/parser/parser.factor
+++ b/extra/smalltalk/parser/parser.factor
@@ -45,7 +45,7 @@ Keyword = Identifier:i ":" => [[ i ":" append ]]
 
 KeywordMessageSelector = Keyword+ => [[ concat ]]
 BinarySelectorChar =   "~" | "!" | "@" | "%" | "&" | "*" | "-" | "+"
-                     | "=" | "|" | "\" | "<" | ">" | "," | "?" | "/"
+                     | "=" | "|" | "\\" | "<" | ">" | "," | "?" | "/"
 BinaryMessageSelector = BinarySelectorChar+ => [[ concat ]]
 
 OptionalMinus = ("-" => [[ CHAR: - ]])?
@@ -225,4 +225,4 @@ End = !(.)
 
 Program = TopLevelForm End
 
-;EBNF
\ No newline at end of file
+;EBNF