diff --git a/tokenize.l b/tokenize.l
index eef151e..302dd9b 100644
--- a/tokenize.l
+++ b/tokenize.l
@@ -98,7 +98,7 @@ t                    { yylval = 1; return BOOL;}
 nil                  { yylval = 0; return BOOL; }
 [0-9]+               { yylval = atoi(yytext); return NUM; }
 [ \t\n]              { /* ignore white space */ }
-\".*\"               { return STR; }
+\"[^\"]*\"               { return STR; }
 [a-zA-Z][a-zA-Z0-9]* { return SYM; }
 .                    { err(1, "invalid symbol: %s\n", yytext); }
 %%