diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index c8eae0e8..e0430485 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -172,7 +172,7 @@ else: {
   return ELSECOL;
 }
 
-({ALPHA}{ALNUM}*|[']({ALNUM}|[-])*[']) {
+({ALPHA}{ALNUM}*|[']({ALNUM}|[-]|[\.])*[']) {
   if(*yytext == '\'') {
     yytext[yyleng-1] = 0;
     yytext++;