diff --git a/packages/checks/default.nix b/packages/checks/default.nix
index 02b9853..9909e51 100644
--- a/packages/checks/default.nix
+++ b/packages/checks/default.nix
@@ -1,7 +1,7 @@
 { self, ... }:
 
 {
-  perSystem = { filters, pkgs, self', ... }: {
+  perSystem = { filters, pkgs, self', timeTravel', ... }: {
     checks = filters.doFilter filters.checks {
       keycloak = pkgs.callPackage ./keycloak-custom-jre.nix {
         jre = self'.packages.jre17_standard;
@@ -11,6 +11,11 @@
         inherit (self) nixosModules;
         inherit (self'.packages) postgresql;
       };
+      patroni-migration = pkgs.callPackage ./patroni-migration.nix {
+        previous = timeTravel' "486161b78e45e94a6f314b65bb05080605f0cd01";
+        inherit (self) nixosModules;
+        inherit (self'.packages) postgresql;
+      };
       searxng = pkgs.callPackage ./searxng.nix {
         inherit (self'.packages) searxng;
       };
diff --git a/packages/checks/patroni-migration.nix b/packages/checks/patroni-migration.nix
new file mode 100644
index 0000000..b075ca6
--- /dev/null
+++ b/packages/checks/patroni-migration.nix
@@ -0,0 +1,261 @@
+{ nixosTest, nixosModules, postgresql, previous }:
+
+nixosTest (
+  let
+    pgOld = previous.packages.postgresql;
+    pgNew = postgresql;
+
+    nodesIps = [
+      "192.168.1.1"
+      "192.168.1.2"
+      "192.168.1.3"
+    ];
+
+    createNode = index: postgresql: { pkgs, ... }:
+      let
+        ip = builtins.elemAt nodesIps index; # since we already use IPs to identify servers
+      in
+      {
+        imports = [
+          nixosModules.patroni
+          nixosModules.systemd-extras
+        ];
+
+        networking.interfaces.eth1.ipv4.addresses = pkgs.lib.mkOverride 0 [
+          { address = ip; prefixLength = 16; }
+        ];
+
+        networking.firewall.allowedTCPPorts = [ 5432 8008 5010 ];
+
+        environment.systemPackages = [ pkgs.jq ];
+
+        systemd.tmpfiles.rules = [
+          "d /data 0700 patroni patroni - -"
+        ];
+        services.patroni = {
+
+          enable = true;
+
+          migrations = {
+            enable = true;
+          };
+
+          dataDir = "/data/patroni";
+          postgresqlDataDir = "/data/postgres";
+
+          postgresqlPackage = postgresql.withPackages (p: [ p.pg_safeupdate ]);
+
+          scope = "cluster1";
+          name = "node${toString(index + 1)}";
+          nodeIp = ip;
+          otherNodesIps = builtins.filter (h: h != ip) nodesIps;
+          softwareWatchdog = true;
+
+          settings = {
+            bootstrap = {
+              dcs = {
+                ttl = 30;
+                loop_wait = 10;
+                retry_timeout = 10;
+                maximum_lag_on_failover = 1048576;
+              };
+              initdb = [
+                { encoding = "UTF8"; }
+                "data-checksums"
+              ];
+            };
+
+            postgresql = {
+              use_pg_rewind = true;
+              use_slots = true;
+              authentication = {
+                replication = {
+                  username = "replicator";
+                };
+                superuser = {
+                  username = "postgres";
+                };
+                rewind = {
+                  username = "rewind";
+                };
+              };
+              parameters = {
+                listen_addresses = "${ip}";
+                wal_level = "replica";
+                hot_standby_feedback = "on";
+                unix_socket_directories = "/tmp";
+              };
+              pg_hba = [
+                "host replication replicator 192.168.1.0/24 md5"
+                # Unsafe, do not use for anything other than tests
+                "host all all 0.0.0.0/0 trust"
+              ];
+            };
+
+            consul = {
+              host = "192.168.1.4:8500";
+              register_service = true;
+            };
+          };
+
+          environmentFiles = {
+            PATRONI_REPLICATION_PASSWORD = pkgs.writeText "replication-password" "postgres";
+            PATRONI_SUPERUSER_PASSWORD = pkgs.writeText "superuser-password" "postgres";
+            PATRONI_REWIND_PASSWORD = pkgs.writeText "rewind-password" "postgres";
+          };
+        };
+
+        # We always want to restart so the tests never hang
+        systemd.services.patroni.serviceConfig.StartLimitIntervalSec = 0;
+      };
+  in
+  {
+    name = "patroni";
+
+    nodes = {
+      node1 = createNode 0 pgOld;
+      node2 = createNode 1 pgOld;
+      node3 = createNode 2 pgOld;
+      node1new = createNode 0 pgNew;
+      node2new = createNode 1 pgNew;
+      node3new = createNode 2 pgNew;
+
+      consul = { pkgs, ... }: {
+
+        networking.interfaces.eth1.ipv4.addresses = pkgs.lib.mkOverride 0 [
+          { address = "192.168.1.4"; prefixLength = 16; }
+        ];
+
+        services.consul = {
+          enable = true;
+          extraConfig = {
+            addresses.http = "192.168.1.4";
+            server = true;
+            bind_addr = "192.168.1.4";
+            bootstrap_expect = 1;
+          };
+        };
+
+        networking.firewall.allowedTCPPorts = [ 8500 ];
+      };
+
+      client = { pkgs, ... }: {
+        environment.systemPackages = [ postgresql ];
+
+        systemd.services.db-writer = {
+          wantedBy = [ "multi-user.target" ];
+          after = [ "haproxy.service" ];
+          requires = [ "haproxy.service" ];
+          serviceConfig.Type = "oneshot";
+          script = ''
+            set +e
+            while ! ${pgNew}/bin/psql -h 127.0.0.1 -U postgres --command='create table dummy2 as select * from generate_series(1, 10) as val;'; do
+              sleep 2;
+            done
+            i=11
+            version="$(${pgNew}/bin/psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command='select version();')"
+            while sleep .5; do
+              newVersion=""
+              while [[ -z "$newVersion" ]]; do
+                newVersion="$(${pgNew}/bin/psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command='select version();')"
+                sleep .5
+              done
+              echo $newVersion
+
+              while ! ${pgNew}/bin/psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command="insert into dummy2 values($i);"; do
+                retrying write for value $i
+                sleep .5
+              done
+              echo wrote value $i
+              i=$((i+1))
+
+              if [[ "$newVersion" != "$version" ]]; then
+                echo new version detected, quitting
+                exit 0
+              fi
+            done
+          '';
+        };
+        networking.interfaces.eth1.ipv4.addresses = pkgs.lib.mkOverride 0 [
+          { address = "192.168.2.1"; prefixLength = 16; }
+        ];
+
+        services.haproxy = {
+          enable = true;
+          config = ''
+            global
+                maxconn 100
+
+            defaults
+                log global
+                mode tcp
+                retries 2
+                timeout client 30m
+                timeout connect 4s
+                timeout server 30m
+                timeout check 5s
+
+            listen cluster1
+                bind 127.0.0.1:5432
+                option httpchk
+                http-check expect status 200
+                default-server inter 3s fall 3 rise 2 on-marked-down shutdown-sessions
+                ${builtins.concatStringsSep "\n" (map (ip: "server postgresql_${ip}_5432 ${ip}:5432 maxconn 100 check port 8008") nodesIps)}
+          '';
+        };
+      };
+    };
+
+
+
+    testScript = /*python*/ ''
+      nodes = [node1, node2, node3]
+      nodes_new = [node1new, node2new, node3new]
+      node_pairs = [
+          (1, node1, node1new),
+          (2, node2, node2new),
+          (3, node3, node3new)
+      ]
+
+      def wait_for_all_nodes_ready(nodes=nodes, expected_replicas=2):
+          booted_nodes = filter(lambda node: node.booted, nodes)
+          for node in booted_nodes:
+              print(node.succeed("patronictl list cluster1"))
+              node.wait_until_succeeds(f"[ $(patronictl list -f json cluster1 | jq 'length') == {expected_replicas + 1} ]")
+              node.wait_until_succeeds("[ $(patronictl list -f json cluster1 | jq 'map(select(.Role | test(\"^Leader$\"))) | map(select(.State | test(\"^running$\"))) | length') == 1 ]")
+              node.wait_until_succeeds(f"[ $(patronictl list -f json cluster1 | jq 'map(select(.Role | test(\"^Replica$\"))) | map(select(.State | test(\"^running$\"))) | length') == {expected_replicas} ]")
+              print(node.succeed("patronictl list cluster1"))
+          client.wait_until_succeeds("psql -h 127.0.0.1 -U postgres --command='select 1;'")
+
+      def run_dummy_queries():
+          client.succeed("psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command='insert into dummy(val) values (101);'")
+          client.succeed("test $(psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command='select val from dummy where val = 101;') -eq 101")
+          client.succeed("psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command='delete from dummy where val = 101;'")
+
+      consul.start()
+      client.start()
+      for node in nodes:
+        node.start()
+
+      with subtest("should bootstrap a new patroni cluster"):
+          wait_for_all_nodes_ready()
+
+      with subtest("should be able to insert and select"):
+          client.succeed("psql -h 127.0.0.1 -U postgres --command='create table dummy as select * from generate_series(1, 100) as val;'")
+          client.succeed("test $(psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command='select count(distinct val) from dummy;') -eq 100")
+
+      with subtest("should upgrade to a new major version"):
+          for (i, old, new) in node_pairs:
+              old.succeed("systemctl stop patroni")
+              old.succeed(f"tar cf /tmp/shared/data{i}.tar /data")
+              old.shutdown()
+              new.succeed(f"tar xf /tmp/shared/data{i}.tar -C /")
+
+      with subtest("should be able to read and write after upgrade"):
+          wait_for_all_nodes_ready(nodes=nodes_new)
+          run_dummy_queries()
+
+      with subtest("should not have lost any data"):
+          client.succeed("test $(psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command='select count(distinct val) from dummy2;') -eq $(psql -h 127.0.0.1 -U postgres --pset='pager=off' --tuples-only --command='select max(val) from dummy2;')")
+    '';
+  })