diff --git a/impermanence.pl b/impermanence.pl
index 09ac409..e8d54f9 100755
--- a/impermanence.pl
+++ b/impermanence.pl
@@ -245,6 +245,19 @@ sub call_chezmoi
   }
 }
 
+sub get_uid
+{
+  my $user = shift;
+  my $s    = `userinfo $user`;
+
+  if ( $s =~ /uid\t([0-9]+)/s ) {
+    my $uid = $1;
+    return $uid;
+  } else {
+    trap_error("ERROR: userinfo did not return uid");
+  }
+}
+
 sub main
 {
 
@@ -332,6 +345,8 @@ sub main
   }
 
   if ( $stop && is_mounted($impermanence_home) ) {
+    my $uid = get_uid( $opts{u} );
+    system( "pkill", "-U $uid" );
     my $status = system( "umount", $impermanence_home );
     if ( $status != 0 ) {
       trap_error("umount did exit with status $status");