diff --git a/uri.c b/uri.c
index 950e177b..1ae5768b 100644
--- a/uri.c
+++ b/uri.c
@@ -127,7 +127,7 @@ static void xmlCleanURI(xmlURIPtr uri);
       (((*(p) == '!')) || ((*(p) == '$')) || ((*(p) == '&')) ||		\
        ((*(p) == '(')) || ((*(p) == ')')) || ((*(p) == '*')) ||		\
        ((*(p) == '+')) || ((*(p) == ',')) || ((*(p) == ';')) ||		\
-       ((*(p) == '=')))
+       ((*(p) == '=')) || ((*(p) == '\'')))
 
 /*
  *    gen-delims    = ":" / "/" / "?" / "#" / "[" / "]" / "@"