diff --git a/nixos/modules/services/web-apps/wakapi.nix b/nixos/modules/services/web-apps/wakapi.nix
index ab322cad7aedf..982b572fb2fa7 100644
--- a/nixos/modules/services/web-apps/wakapi.nix
+++ b/nixos/modules/services/web-apps/wakapi.nix
@@ -182,21 +182,21 @@ in
         message = "Either `services.wakapi.passwordSalt` or `services.wakapi.passwordSaltFile` must be set.";
       }
       {
-        assertion = cfg.passwordSalt != null -> cfg.passwordSaltFile != null;
+        assertion = !(cfg.passwordSalt != null && cfg.passwordSaltFile != null);
         message = "Both `services.wakapi.passwordSalt` `services.wakapi.passwordSaltFile` should not be set at the same time.";
       }
       {
-        assertion = cfg.smtpPassword != null -> cfg.smtpPasswordFile != null;
+        assertion = !(cfg.smtpPassword != null && cfg.smtpPasswordFile != null);
         message = "Both `services.wakapi.smtpPassword` `services.wakapi.smtpPasswordFile` should not be set at the same time.";
       }
       {
-        assertion = cfg.db.createLocally -> cfg.db.dialect != null;
+        assertion = cfg.database.createLocally -> cfg.settings.db.dialect != null;
         message = "`services.wakapi.database.createLocally` is true, but a database dialect is not set!";
       }
     ];
 
     warnings = [
-      (lib.optionalString (cfg.db.createLocall -> cfg.db.dialect != "postgres") ''
+      (lib.optionalString (cfg.database.createLocally -> cfg.settings.db.dialect != "postgres") ''
         You have enabled automatic database configuration, but the database dialect is not set to "posgres".
 
         The Wakapi module only supports for PostgreSQL. Please set `services.wakapi.database.createLocally`
diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 0934c25ff9d6b..fb85df8808f1e 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -1108,6 +1108,7 @@ in {
   vscode-remote-ssh = handleTestOn ["x86_64-linux"] ./vscode-remote-ssh.nix {};
   vscodium = discoverTests (import ./vscodium.nix);
   vsftpd = handleTest ./vsftpd.nix {};
+  wakapi = handleTest ./wakapi.nix {};
   warzone2100 = handleTest ./warzone2100.nix {};
   wasabibackend = handleTest ./wasabibackend.nix {};
   wastebin = handleTest ./wastebin.nix {};
diff --git a/nixos/tests/wakapi.nix b/nixos/tests/wakapi.nix
new file mode 100644
index 0000000000000..2e611a986e303
--- /dev/null
+++ b/nixos/tests/wakapi.nix
@@ -0,0 +1,40 @@
+import ./make-test-python.nix (
+  { lib, ... }:
+  {
+    name = "Wakapi";
+
+    nodes.machine = {
+      services.wakapi = {
+        enable = true;
+        settings = {
+          server.port = 3000; # upstream default, set explicitly in case upstream changes it
+
+          db = {
+            dialect = "postgres"; # `createLocally` only supports postgres
+            host = "/run/postgresql";
+            port = 5432; # service will fail if port is not set
+            name = "wakapi";
+            user = "wakapi";
+          };
+        };
+
+        database.createLocally = true;
+
+        # Created with `cat /dev/urandom | LC_ALL=C tr -dc 'a-zA-Z0-9' | fold -w ${1:-32} | head -n 1`
+        # Prefer passwordSaltFile in production.
+        passwordSalt = "NpqCY7eY7fMoIWYmPx5mAgr6YoSlXSuI";
+      };
+    };
+
+    # Test that the service is running and that it is reachable.
+    # This is not very comprehensive for a test, but it should
+    # catch very basic mistakes in the module.
+    testScript = ''
+      machine.wait_for_unit("wakapi.service")
+      machine.wait_for_open_port(3000)
+      machine.succeed("curl --fail http://localhost:3000")
+    '';
+
+    meta.maintainers = [ lib.maintainers.NotAShelf ];
+  }
+)