diff --git a/src/db/sqlite/SqliteInterface.ts b/src/db/sqlite/SqliteInterface.ts
index b61f9ba..3775863 100644
--- a/src/db/sqlite/SqliteInterface.ts
+++ b/src/db/sqlite/SqliteInterface.ts
@@ -392,6 +392,13 @@ export class SqliteInterface implements BackendDbInterface {
       WHERE "uid" = ${{ uuid: uid }}
     `);
   }
+  async deleteSession(token: `as_${string}`): Promise<void> {
+    this.#checkReadonly();
+    this.#db.run(sql`
+      DELETE FROM "sessions"
+      WHERE "token" = ${{ text: token }}
+    `);
+  }
 
   #getApikeyByToken(token: `at_${string}`): ClientApikey {
     const apikey = selectClientApikey(
diff --git a/src/db/types/DbInterface.ts b/src/db/types/DbInterface.ts
index 44db796..c85dc75 100644
--- a/src/db/types/DbInterface.ts
+++ b/src/db/types/DbInterface.ts
@@ -85,6 +85,7 @@ export interface BackendDbInterface extends DbInterface {
   // auth by session
   getUserBySession(token: `as_${string}`): Promise<ClientUser>;
   createSession(uid: string): Promise<`as_${string}`>;
+  deleteSession(token: `as_${string}`): Promise<void>;
 
   // auth by apikey
   getUserByApikey(token: `at_${string}`): Promise<[ClientUser, ClientApikey]>;
@@ -98,6 +99,7 @@ export function isBackendInterface(db: DbInterface): db is BackendDbInterface {
         "getUserByLogin",
         "getUserBySession",
         "createSession",
+        "deleteSession",
         "getUserByApikey",
       ] as const
     ).every(
diff --git a/src/webapi/apirouter.ts b/src/webapi/apirouter.ts
index be970cb..6c5c9ac 100644
--- a/src/webapi/apirouter.ts
+++ b/src/webapi/apirouter.ts
@@ -28,6 +28,8 @@ export function apirouter(db: BackendDbInterface): KoaRouter {
   });
   router.post("/auth/logout", authenticate(db), async (ctx) => {
     if (ctx.session!.source !== "session") throw new InvalidAbodeError();
+    const token = ctx.cookies.get("abode_session");
+    if (token) await db.deleteSession(token as `as_${string}`);
     ctx.cookies.set("abode_session", "", { expires: new Date("1970-01-01") });
     ctx.status = 204;
   });
diff --git a/test/backends/api/auth-http.test.ts b/test/backends/api/auth-http.test.ts
index 9d76b2b..dbe287e 100644
--- a/test/backends/api/auth-http.test.ts
+++ b/test/backends/api/auth-http.test.ts
@@ -74,7 +74,7 @@ describe("api backend: auth over HTTP", async () => {
     assert.equal(res.status, 401);
   });
 
-  it("POST /auth/logout clears the session cookie", async () => {
+  it("POST /auth/logout clears the cookie and invalidates the session server-side", async () => {
     const login = await fetch(`${server.url}/auth/login`, {
       method: "POST",
       headers: { "Content-Type": "application/json" },
@@ -88,6 +88,11 @@ describe("api backend: auth over HTTP", async () => {
     });
     assert.equal(logout.status, 204);
     assert.equal(getCookie(logout, "abode_session"), "");
+
+    const self = await fetch(`${server.url}/auth/self`, {
+      headers: { Cookie: `abode_session=${cookie}` },
+    });
+    assert.equal(self.status, 401, "session was invalidated server-side, not just the cookie cleared");
   });
 
   it("POST /auth/clear-sessions invalidates outstanding session cookies", async () => {
diff --git a/test/tools/authenticate.test.ts b/test/tools/authenticate.test.ts
index 1a3e52d..6fa6a8a 100644
--- a/test/tools/authenticate.test.ts
+++ b/test/tools/authenticate.test.ts
@@ -71,6 +71,7 @@ function makeMockDb(
     getUserByLogin: async () => { throw new NotFoundAbodeError(); },
     getUserBySession: async () => { throw new NotFoundAbodeError(); },
     createSession: async () => `as_${"0".repeat(32)}`,
+    deleteSession: async () => {},
     getUserByApikey: async () => { throw new NotFoundAbodeError(); },
     ...overrides,
   };