diff --git a/lib/rtsp.c b/lib/rtsp.c
index eb60ff782..ed3fd64c7 100644
--- a/lib/rtsp.c
+++ b/lib/rtsp.c
@@ -799,12 +799,12 @@ CURLcode Curl_rtsp_parseheader(struct connectdata *conn,
       /* If the Session ID is not set, and we find it in a response, then set
        * it.
        *
-       * Allow any content, up to the field seperator or end of line. RFC 2326
-       * isn't 100% clear on the session ID and for example gstreamer does
-       * url-encoded session ID's not covered by the standard.
+       * Allow any non whitespace content, up to the field seperator or end of
+       * line. RFC 2326 isn't 100% clear on the session ID and for example
+       * gstreamer does url-encoded session ID's not covered by the standard.
        */
       char *end = start;
-      while(*end && *end != ';')
+      while(*end && *end != ';' && !ISSPACE(*end))
         end++;
 
       /* Copy the id substring into a new buffer */