diff --git a/src/macports1.0/macports.tcl b/src/macports1.0/macports.tcl
index 5b9dd9d3fb..d29dae8b63 100644
--- a/src/macports1.0/macports.tcl
+++ b/src/macports1.0/macports.tcl
@@ -2833,6 +2833,10 @@ proc mportexec {mport target} {
         # install them
         set result [dlist_eval $dlist _mportactive [list _mportexec activate]]
 
+        if {[getuid] == 0 && [geteuid] != 0} {
+            seteuid 0; setegid 0
+        }
+
         registry::exclusive_unlock
 
         if {$result ne ""} {
@@ -2902,6 +2906,11 @@ proc mportexec {mport target} {
         macports::pop_log
     }
 
+    # Regain privileges that may have been dropped while running the target.
+    if {[getuid] == 0 && [geteuid] != 0} {
+        seteuid 0; setegid 0
+    }
+
     return $result
 }