diff --git a/source/daemons/shepherd/shepherd.c b/source/daemons/shepherd/shepherd.c
index 5af1463..e7b2831 100644
--- a/source/daemons/shepherd/shepherd.c
+++ b/source/daemons/shepherd/shepherd.c
@@ -299,17 +299,24 @@ static int handle_io_file(const char* file, const char* owner, bool rw) {
       }
    }
 
-   /* reset egid and euid to the stored values */
-   if (sge_seteuid(old_euid) != 0) {
-      shepherd_trace("Cannot reset euid %s due to %s", owner, strerror(errno));
-      SGE_CLOSE(fd);
+   /* set effective user-id to root again, because only root is allowed to change
+    * the euid to any other than the current user-id.   */
+   if (sge_seteuid(SGE_SUPERUSER_UID) != 0) {
+      shepherd_trace("Cannot become root due to %s", strerror(errno));
       return -1;
    }
+
+   /* reset egid and euid to the stored values (e.g. those of the sgeadmin user) */
    if (sge_setegid(old_egid) != 0) {
       shepherd_trace("Cannot reset egid %s due to %s", owner, strerror(errno));
       SGE_CLOSE(fd);
       return -1;
    }
+   if (sge_seteuid(old_euid) != 0) {
+      shepherd_trace("Cannot reset euid %s due to %s", owner, strerror(errno));
+      SGE_CLOSE(fd);
+      return -1;
+   }
 
    return fd;
 }