diff --git a/btrbk b/btrbk
index f82699d..2fb483e 100755
--- a/btrbk
+++ b/btrbk
@@ -171,7 +171,7 @@ my %table_formats = (
 my %url_cache;       # map URL to btr_tree node
 my %fstab_cache;     # map HOST to btrfs mount points
 my %uuid_cache;      # map UUID to btr_tree node
-my %symlink;         # map URL to REAL_URL (symlink target)
+my %realpath_cache;  # map URL to realpath (symlink target)
 
 my $dryrun;
 my $loglevel = 1;
@@ -566,7 +566,7 @@ sub btrfs_subvolume_show($)
     $real_path = $1;
     DEBUG "Real path for subvolume \"$vol->{PRINT}\" is: $real_path" if($real_path ne $path);
     return undef unless(check_file($real_path, { absolute => 1 }));
-    $symlink{$vol->{URL}} = $vol->{URL_PREFIX} . $real_path if($real_path ne $path);
+    $realpath_cache{$vol->{URL}} = $real_path if($real_path ne $path);
   }
   else {
     $real_path = $path;
@@ -1148,13 +1148,10 @@ sub btrfs_mountpoint($)
   TRACE "fstab_cache " . ($mounts ? "HIT" : "MISS") . ": $host";
 
   # get real path
-  my $path = $symlink{$vol->{URL}};
-  if($path) {
-    die unless($path =~ s/^\Q$vol->{URL_PREFIX}\E//);
-  }
-  else {
+  my $path = $realpath_cache{$vol->{URL}};
+  unless($path) {
     $path = system_realpath($vol);
-    $symlink{$vol->{URL}} = $vol->{URL_PREFIX} . $path;
+    $realpath_cache{$vol->{URL}} = $path;
   }
   return (undef, undef, undef) unless($path);
 
@@ -1452,7 +1449,8 @@ sub vinfo_init_root($;@)
   $tree_root = $url_cache{$vol->{URL}};
   TRACE "url_cache " . ($tree_root ? "HIT" : "MISS") . ": URL=$vol->{URL}";
   unless($tree_root) {
-    if(my $real_url = $symlink{$vol->{URL}}) {
+    if(my $real_path = $realpath_cache{$vol->{URL}}) {
+      my $real_url = $vol->{URL_PREFIX} . $real_path;
       $tree_root = $url_cache{$real_url};
       TRACE "url_cache " . ($tree_root ? "HIT" : "MISS") . ": REAL_URL=$real_url";
     }
@@ -1463,9 +1461,9 @@ sub vinfo_init_root($;@)
     # url_cache miss, read the subvolume detail
     my $detail = btrfs_subvolume_show($vol);
     if($detail) {
-      my $real_url = $symlink{$vol->{URL}};
+      my $real_path = $realpath_cache{$vol->{URL}};
       push @fill_cache, $vol->{URL};
-      push @fill_cache, $real_url if($real_url && (not $url_cache{$real_url}));
+      push @fill_cache, $vol->{URL_PREFIX} . $real_path if($real_path && (not $url_cache{$vol->{URL_PREFIX} . $real_path}));
 
       # check uuid_cache
       if($detail->{uuid}) {
@@ -3462,7 +3460,7 @@ MAIN:
       # check for duplicate snapshot locations
       my $snapdir = config_key($svol, "snapshot_dir", postfix => '/') // "";
       my $snapshot_basename = config_key($svol, "snapshot_name") // die;
-      my $snapshot_target = ($symlink{$sroot->{URL}} // $sroot->{URL}) . '/' . $snapdir . $snapshot_basename;
+      my $snapshot_target = $sroot->{URL_PREFIX} . ($realpath_cache{$sroot->{URL}} // $sroot->{PATH}) . '/' . $snapdir . $snapshot_basename;
       if(my $prev = $snapshot_check{$snapshot_target}) {
         ERROR "Subvolume \"$prev\" and \"$svol->{PRINT}\" will create same snapshot: $snapshot_target";
         ERROR "Please fix \"snapshot_name\" configuration options!";
@@ -3472,7 +3470,7 @@ MAIN:
 
       foreach my $droot (vinfo_subsection($svol, 'target')) {
         # check for duplicate snapshot locations
-        my $snapshot_backup_target = ($symlink{$droot->{URL}} // $droot->{URL}) . '/' . $snapshot_basename;
+        my $snapshot_backup_target = $droot->{URL_PREFIX} . ($realpath_cache{$droot->{URL}} // $droot->{PATH}) . '/' . $snapshot_basename;
         if(my $prev = $backup_check{$snapshot_backup_target}) {
           ERROR "Subvolume \"$prev\" and \"$svol->{PRINT}\" will create same backup target: $snapshot_backup_target";
           ERROR "Please fix \"snapshot_name\" or \"target\" configuration options!";