diff --git a/test/vm/ldap.nix b/test/vm/ldap.nix
index 6b8ee60..967757a 100644
--- a/test/vm/ldap.nix
+++ b/test/vm/ldap.nix
@@ -34,6 +34,7 @@
 
     start_all()
     server.wait_for_unit("lldap.service")
+    server.wait_for_open_port(${toString nodes.server.services.lldap.settings.http_port})
 
     with subtest("fail without authenticating"):
         client.fail(
diff --git a/test/vm/monitoring.nix b/test/vm/monitoring.nix
index 12723ce..e9ee204 100644
--- a/test/vm/monitoring.nix
+++ b/test/vm/monitoring.nix
@@ -28,6 +28,7 @@
     testScript = { nodes, ... }: ''
     start_all()
     machine.wait_for_unit("grafana.service")
+    machine.wait_for_open_port(${toString nodes.machine.services.grafana.settings.server.http_port})
 
     def curl_req(password, wantStatus, endpoint):
         response = machine.wait_until_succeeds("curl -i http://admin:{password}@localhost:3000{endpoint}".format(password=password, endpoint=endpoint), timeout=10)
diff --git a/test/vm/postgresql.nix b/test/vm/postgresql.nix
index c8ef789..61872c3 100644
--- a/test/vm/postgresql.nix
+++ b/test/vm/postgresql.nix
@@ -19,6 +19,7 @@
     testScript = { nodes, ... }: ''
     start_all()
     machine.wait_for_unit("postgresql.service")
+    machine.wait_for_open_port(5432)
 
     def peer_cmd(user, database):
         return "sudo -u me psql -U {user} {db} --command \"\"".format(user=user, db=database)
@@ -60,6 +61,7 @@
     testScript = { nodes, ... }: ''
     start_all()
     machine.wait_for_unit("postgresql.service")
+    machine.wait_for_open_port(5432)
 
     def peer_cmd(user, database):
         return "sudo -u me psql -U {user} {db} --command \"\"".format(user=user, db=database)
@@ -101,6 +103,7 @@
     testScript = { nodes, ... }: ''
     start_all()
     machine.wait_for_unit("postgresql.service")
+    machine.wait_for_open_port(5432)
 
     def peer_cmd(user, database):
         return "sudo -u me psql -U {user} {db} --command \"\"".format(user=user, db=database)
@@ -147,6 +150,7 @@
     testScript = { nodes, ... }: ''
     start_all()
     machine.wait_for_unit("postgresql.service")
+    machine.wait_for_open_port(5432)
 
     def peer_cmd(user, database):
         return "sudo -u me psql -U {user} {db} --command \"\"".format(user=user, db=database)