diff --git a/src/XrdThrottle/XrdThrottleFile.cc b/src/XrdThrottle/XrdThrottleFile.cc
index afa4c493e2b..27d4d1a83e1 100644
--- a/src/XrdThrottle/XrdThrottleFile.cc
+++ b/src/XrdThrottle/XrdThrottleFile.cc
@@ -32,7 +32,7 @@ File::File(const char                     *user,
      m_sfs(sfs),
 #endif
      m_uid(0),
-     m_user(user),
+     m_user(user ? user : ""),
      m_throttle(throttle),
      m_eroute(eroute)
 {}