diff --git a/lib/Lacuna/RPC/Empire.pm b/lib/Lacuna/RPC/Empire.pm
index f996f13c..bb15cf33 100644
--- a/lib/Lacuna/RPC/Empire.pm
+++ b/lib/Lacuna/RPC/Empire.pm
@@ -1235,6 +1235,9 @@ sub authorize_sitters
 {
     my ($self, $session_id, $opts) = @_;
     my $session  = $self->get_session({session_id => $session_id});
+    if ($session->is_sitter) {
+        confess [1015, 'Sitters cannot manage sitters.'];
+    }
     $session->check_captcha;
 
     my $baby = $session->current_empire;
@@ -1309,6 +1312,9 @@ sub deauthorize_sitters {
     my ($self, $session_id, $opts) = @_;
 
     my $session  = $self->get_session({session_id => $session_id});
+    if ($session->is_sitter) {
+        confess [1015, 'Sitters cannot manage sitters.'];
+    }
     my $baby = $session->current_empire;
 
     my $baby_id = $session->empire_id;
diff --git a/t/bugs/0043_SittersCannotManageSitters.t b/t/bugs/0043_SittersCannotManageSitters.t
new file mode 100644
index 00000000..c6e389d6
--- /dev/null
+++ b/t/bugs/0043_SittersCannotManageSitters.t
@@ -0,0 +1,50 @@
+use lib '..','../../lib';
+use Test::More tests => 6;
+use 5.010;
+
+use strict;
+use warnings;
+
+use TestHelper;
+TestHelper->clear_all_test_empires;
+
+# BUG someone logged in with an empire's sitter password could authorize more sitters on
+# that empire, or remove the ones its owner had authorized. Sitters already cannot change
+# the password or the sitter password, so they should not manage the sitter list either.
+
+my $owner = TestHelper->new->generate_test_empire;
+my $empire = $owner->empire;
+$empire->sitter_password('testsitter');
+$empire->update;
+
+my $other = TestHelper->new(empire_name => 'TLE Test Sitter')->generate_test_empire;
+my $other_id = $other->empire->id;
+
+my $result = $owner->post('empire', 'login', [$owner->empire_name, 'testsitter', 'Anonymous']);
+my $sitter_session_id = $result->{result}{session_id};
+ok($sitter_session_id, 'logged in with the sitter password');
+
+# Solve the captcha so that, without the guard, authorize_sitters would go through.
+Lacuna->cache->set('captcha', $sitter_session_id, { guid => 1111, solution => 1111 }, 60 * 15);
+$owner->post('captcha', 'solve', [$sitter_session_id, 1111, 1111]);
+
+$result = $owner->post('empire', 'authorize_sitters', [$sitter_session_id, { empires => [$other_id] }]);
+is($result->{error}{code}, 1015, 'a sitter cannot authorize sitters');
+is($empire->sitters->count, 0, 'and no sitter was added');
+
+my %key  = (baby_id => $empire->id, sitter_id => $other_id);
+my $auths = Lacuna->db->resultset('SitterAuths');
+my $auth  = $auths->find(\%key) // $auths->new(\%key);
+$auth->reauthorise;
+$auth->update_or_insert;
+
+$result = $owner->post('empire', 'deauthorize_sitters', [$sitter_session_id, { deauthorize_all => 1 }]);
+is($result->{error}{code}, 1015, 'a sitter cannot deauthorize sitters');
+ok($auth->get_from_storage->expiry > DateTime->now, 'and the owner\'s sitter is still authorized');
+
+$result = $owner->post('empire', 'deauthorize_sitters', [$owner->session->id, { empires => [$other_id] }]);
+is($result->{error}, undef, 'the owner can still deauthorize sitters');
+
+END {
+    TestHelper->clear_all_test_empires;
+}