diff --git a/lib/Synergy/Reactor/InABox.pm b/lib/Synergy/Reactor/InABox.pm
index b597a3cd..fc00ada3 100644
--- a/lib/Synergy/Reactor/InABox.pm
+++ b/lib/Synergy/Reactor/InABox.pm
@@ -159,25 +159,15 @@ command box => {
 
   my %switches = map { my ($k, @rest) = @$_; $k => \@rest } @$switches;
 
-  if (!exists $switches{datacentre}) {
-    if (exists $switches{datacenter}) {
-      $switches{datacentre} = delete $switches{datacenter};
-    }
-    elsif (exists $switches{region}) {
-      $switches{datacentre} = delete $switches{region};
-    }
-  }
+  # Special handling for aliased datacenter / datacentre / region switch
+  my @got = grep { exists $switches{$_} } qw(datacenter datacentre region);
 
-  # This should be simplified into a more generic "validate and normalize
-  # switches" call. -- rjbs, 2023-10-20
-  # I've made this not more generic but more clever: We first normalize to
-  # datacentre above and then check if one of the aliases is still hanging
-  # around which means a duplicate alias was passed. -- lerlacher, 2024-07-27
-  # Normalize datacentre
-  if (exists $switches{datacenter} || exists $switches{region}) {
-    return await $event->error_reply("Please pass only one of /datacenter or /datacentre or /region!");
+  if (@got > 1) {
+    die "The following options are mutually exclusive: @got\n";
   }
 
+  $switches{datacentre} = delete $switches{$got[0]};
+
   for my $k (qw( version tag size datacentre )) {
     next unless $switches{$k};
     $switches{$k} = $switches{$k}[0];