diff --git a/CHANGELOG b/CHANGELOG
index 961082f..caf1e61 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -5,13 +5,14 @@ New features:
 - Support for the Fever protocol (see README.md for details)
 - Command line functionality for clearing a password, disabling the account
 - Command line options for dealing with Fever passwords
-- Command line functionality for exporting subscriptions to OPML
+- Command line functionality for importing and exporting OPML
 - Command line functionality for cron-based feed updating
 - Command line documentation of all commands and options
 
 Bug fixes:
 - Treat command line option -h the same as --help
 - Sort Tiny Tiny RSS special feeds according to special ordering
+- Invalidate sessions when passwords are changed
 
 Version 0.7.1 (2019-03-25)
 ==========================
diff --git a/lib/Database.php b/lib/Database.php
index daca234..10e66eb 100644
--- a/lib/Database.php
+++ b/lib/Database.php
@@ -340,15 +340,21 @@ class Database {
      * This function can be used to explicitly invalidate a session after a user logs out
      *
      * @param string $user The user who owns the session to be destroyed
-     * @param string $id The identifier of the session to destroy
+     * @param string|null $id The identifier of the session to destroy
      */
-    public function sessionDestroy(string $user, string $id): bool {
+    public function sessionDestroy(string $user, string $id = null): bool {
         // If the user isn't authorized to perform this action then throw an exception.
         if (!Arsse::$user->authorize($user, __FUNCTION__)) {
             throw new User\ExceptionAuthz("notAuthorized", ["action" => __FUNCTION__, "user" => $user]);
         }
-        // delete the session and report success.
-        return (bool) $this->db->prepare("DELETE FROM arsse_sessions where id = ? and \"user\" = ?", "str", "str")->run($id, $user)->changes();
+        if (is_null($id)) {
+            // delete all sessions and report success unconditionally if no identifier was specified
+            $this->db->prepare("DELETE FROM arsse_sessions where \"user\" = ?", "str")->run($user);
+            return true;
+        } else {
+            // otherwise delete only the specified session and report success.
+            return (bool) $this->db->prepare("DELETE FROM arsse_sessions where id = ? and \"user\" = ?", "str", "str")->run($id, $user)->changes();
+        }
     }
 
     /** Resumes a session, returning available session data
diff --git a/lib/User.php b/lib/User.php
index 4f52980..691d6fa 100644
--- a/lib/User.php
+++ b/lib/User.php
@@ -110,6 +110,8 @@ class User {
         if (Arsse::$db->userExists($user)) {
             // if the password change was successful and the user exists, set the internal password to the same value
             Arsse::$db->userPasswordSet($user, $out);
+            // also invalidate any current sessions for the user
+            Arsse::$db->sessionDestroy($user);
         }
         return $out;
     }
@@ -123,6 +125,8 @@ class User {
         if (Arsse::$db->userExists($user)) {
             // if the password change was successful and the user exists, set the internal password to the same value
             Arsse::$db->userPasswordSet($user, null);
+            // also invalidate any current sessions for the user
+            Arsse::$db->sessionDestroy($user);
         }
         return $out;
     }
diff --git a/tests/cases/Database/SeriesSession.php b/tests/cases/Database/SeriesSession.php
index ad9a45b..9e8a388 100644
--- a/tests/cases/Database/SeriesSession.php
+++ b/tests/cases/Database/SeriesSession.php
@@ -116,6 +116,16 @@ trait SeriesSession {
         $this->assertFalse(Arsse::$db->sessionDestroy($user, $id));
     }
 
+    public function testDestroyAllSessions() {
+        $user = "jane.doe@example.com";
+        $this->assertTrue(Arsse::$db->sessionDestroy($user));
+        $state = $this->primeExpectations($this->data, ['arsse_sessions' => ["id", "created", "expires", "user"]]);
+        unset($state['arsse_sessions']['rows'][0]);
+        unset($state['arsse_sessions']['rows'][1]);
+        unset($state['arsse_sessions']['rows'][2]);
+        $this->compareExpectations(static::$drv, $state);
+    }
+
     public function testDestroyASessionForTheWrongUser() {
         $user = "john.doe@example.com";
         $id = "80fa94c1a11f11e78667001e673b2560";