diff --git a/src/commentscan.l b/src/commentscan.l
index 354627743da..406d966fea6 100644
--- a/src/commentscan.l
+++ b/src/commentscan.l
@@ -920,7 +920,7 @@ FILEECHAR [a-z_A-Z0-9\x80-\xFF\-\+@&#]
 FILE      ({FILESCHAR}*{FILEECHAR}+("."{FILESCHAR}*{FILEECHAR}+)*)|("\""[^\n\"]*"\"")
 ID        "$"?[a-z_A-Z\x80-\xFF][a-z_A-Z0-9\x80-\xFF]*
 LABELID   [a-z_A-Z\x80-\xFF][a-z_A-Z0-9\x80-\xFF\-]*
-CITESCHAR [a-z_A-Z\x80-\xFF]
+CITESCHAR [a-z_A-Z0-9\x80-\xFF]
 CITEECHAR [a-z_A-Z0-9\x80-\xFF\-\+:\/]*
 CITEID    {CITESCHAR}{CITEECHAR}*("."{CITESCHAR}{CITEECHAR}*)*
 SCOPEID   {ID}({ID}*{BN}*"::"{BN}*)*({ID}?)
diff --git a/src/doctokenizer.l b/src/doctokenizer.l
index 31d583c5237..efc058a7452 100644
--- a/src/doctokenizer.l
+++ b/src/doctokenizer.l
@@ -334,7 +334,7 @@ BLANK     [ \t\r]
 ID        "$"?[a-z_A-Z\x80-\xFF][a-z_A-Z0-9\x80-\xFF]*
 LABELID   [a-z_A-Z\x80-\xFF][a-z_A-Z0-9\x80-\xFF\-]*
 PHPTYPE   [\\:a-z_A-Z0-9\x80-\xFF\-]+
-CITESCHAR [a-z_A-Z\x80-\xFF]
+CITESCHAR [a-z_A-Z0-9\x80-\xFF]
 CITEECHAR [a-z_A-Z0-9\x80-\xFF\-\+:\/]*
 CITEID    {CITESCHAR}{CITEECHAR}*("."{CITESCHAR}{CITEECHAR}*)*
 MAILADR   ("mailto:")?[a-z_A-Z0-9.+-]+"@"[a-z_A-Z0-9-]+("."[a-z_A-Z0-9\-]+)+[a-z_A-Z0-9\-]+