diff --git a/README.md b/README.md
index 93927cb0..80ae4e5d 100644
--- a/README.md
+++ b/README.md
@@ -87,6 +87,7 @@ It is recommended you run this service with Docker.
 | `SECONDARY_HOST_(#)_BASE_URL` | Yes      | N/A     | `http://192.168.1.3` or `https://pihole2.example.com`           | The base URL of your secondary Pi-hole, including the scheme (HTTP or HTTPS) and port but not including a following slash. Replace `(#)` with a number, starting at `1`, to add multiple secondary Pi-holes. |
 | `SECONDARY_HOST_(#)_PASSWORD` | Yes      | N/A     | `mypassword2`                                                   | The password used to log in to the admin interface.                                                                                                                                                          |
 | `INTERVAL_MINUTES`            | No       | 30      | Any non-zero positive integer, for example `5`, `30`, or `1440` | How long to wait between synchronizations. Defaults to five minutes. Remember that the DNS server on your secondary servers restarts everytime a sync is performed.                                          |
+| `UPDATE_GRAVITY`              | No       | `true`  | `true`/`false`                                                  | Triggers a gravity update after a backup has been uploaded to a secondary Pi-hole. This updates adlists and restarts gravity.                                                                                |
 | `SYNC_WHITELIST`              | No       | `true`  | `true`/`false`                                                  | Copies the whitelist                                                                                                                                                                                         |
 | `SYNC_REGEX_WHITELIST`        | No       | `true`  | `true`/`false`                                                  | Copies the regex whitelist                                                                                                                                                                                   |
 | `SYNC_BLACKLIST`              | No       | `true`  | `true`/`false`                                                  | Copies the blacklist                                                                                                                                                                                         |
diff --git a/src/client.test.ts b/src/client.test.ts
index 9a088968..711e6d83 100644
--- a/src/client.test.ts
+++ b/src/client.test.ts
@@ -231,8 +231,104 @@ describe('Client', () => {
       });
     });
 
-    test('should upload backup successfully', async () => {
+    test('should throw error if gravity update fails', async () => {
+      teleporter
+        .post('/admin/scripts/pi-hole/php/teleporter.php')
+        .reply(
+          200,
+          'Processed adlist (14 entries)<br>\n' +
+            'Processed adlist group assignments (13 entries)<br>\n' +
+            'Processed blacklist (exact) (0 entries)<br>\n' +
+            'Processed blacklist (regex) (3 entries)<br>\n' +
+            'Processed client (8 entries)<br>\n' +
+            'Processed client group assignments (16 entries)<br>\n' +
+            'Processed local DNS records (41 entries)<br>\n' +
+            'Processed domain_audit (0 entries)<br>\n' +
+            'Processed black-/whitelist group assignments (10 entries)<br>\n' +
+            'Processed group (3 entries)<br>\n' +
+            'Processed whitelist (exact) (4 entries)<br>\n' +
+            'Processed whitelist (regex) (0 entries)<br>\n' +
+            'OK'
+        );
+      teleporter
+        .get('/admin/scripts/pi-hole/php/gravity.sh.php', undefined)
+        .reply(200, '\ndata: \n\ndata:      [✓] TCP (IPv6)\ndata: \ndata: \n\ndata:');
+
+      const expectError = expect(client.uploadBackup(backup)).rejects;
+
+      await expectError.toBeInstanceOf(ErrorNotification);
+      await expectError.toMatchObject({
+        message: 'Failed updating gravity on "http://10.0.0.2".',
+        verbose: {
+          host: 'http://10.0.0.2',
+          status: 200,
+          eventStream: '[✓] TCP (IPv6)'
+        }
+      });
+    });
+
+    test('should upload backup and update gravity successfully', async () => {
+      const syncOptions = jest.spyOn(Config, 'syncOptions', 'get');
+
+      let requestBody = '';
+      teleporter
+        .post('/admin/scripts/pi-hole/php/teleporter.php', (body) => (requestBody = body))
+        .reply(
+          200,
+          'Processed adlist (14 entries)<br>\n' +
+            'Processed adlist group assignments (13 entries)<br>\n' +
+            'Processed blacklist (exact) (0 entries)<br>\n' +
+            'Processed blacklist (regex) (3 entries)<br>\n' +
+            'Processed client (8 entries)<br>\n' +
+            'Processed client group assignments (16 entries)<br>\n' +
+            'Processed local DNS records (41 entries)<br>\n' +
+            'Processed domain_audit (0 entries)<br>\n' +
+            'Processed black-/whitelist group assignments (10 entries)<br>\n' +
+            'Processed group (3 entries)<br>\n' +
+            'Processed whitelist (exact) (4 entries)<br>\n' +
+            'Processed whitelist (regex) (0 entries)<br>\n' +
+            'OK'
+        );
+      teleporter
+        .get('/admin/scripts/pi-hole/php/gravity.sh.php', undefined)
+        .reply(
+          200,
+          '\ndata: \n\ndata:      [✓] TCP (IPv6)\ndata: \ndata: \n\ndata:   [✓] Pi-hole blocking is enabled\ndata: \n\ndata:'
+        );
+
+      const result = await client.uploadBackup(backup);
+
+      expect(result).toStrictEqual(true);
+      expect(syncOptions).toHaveBeenCalled();
+      expect(requestBody).toContain(
+        'name="token"\r\n\r\nabcdefgijklmnopqrstuvwxyzabcdefgijklmnopqrst'
+      );
+      expect(requestBody).toContain('name="whitelist"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="regex_whitelist"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="blacklist"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="regexlist"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="adlist"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="client"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="group"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="auditlog"\r\n\r\nfalse');
+      expect(requestBody).toContain('name="staticdhcpleases"\r\n\r\nfalse');
+      expect(requestBody).toContain('name="localdnsrecords"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="localcnamerecords"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="flushtables"\r\n\r\ntrue');
+      expect(requestBody).toContain('name="action"\r\n\r\nin');
+      expect(requestBody).toContain(
+        'name="zip_file"; filename="backup.tar.gz"\r\nContent-Type: application/octet-stream'
+      );
+      expect(requestBody.match(/Content-Disposition: form-data; name=/g)).toHaveLength(
+        15
+      );
+    });
+
+    test('should not update gravity if `updateGravity` is disabled', async () => {
       const syncOptions = jest.spyOn(Config, 'syncOptions', 'get');
+      const updateGravity = jest
+        .spyOn(Config, 'updateGravity', 'get')
+        .mockReturnValue(false);
 
       let requestBody = '';
       teleporter
@@ -280,6 +376,7 @@ describe('Client', () => {
       expect(requestBody.match(/Content-Disposition: form-data; name=/g)).toHaveLength(
         15
       );
+      updateGravity.mockRestore();
     });
   });
 });
diff --git a/src/client.ts b/src/client.ts
index c2623859..88290b19 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -110,26 +110,53 @@ export class Client {
     form.append('action', 'in');
     form.append('zip_file', backup, 'backup.tar.gz');
 
-    const response = await this.fetch(
+    const uploadResponse = await this.fetch(
       `${this.host.baseUrl}/admin/scripts/pi-hole/php/teleporter.php`,
       {
         body: form,
         method: 'POST'
       }
     );
-    const text = await response.text();
-    if (response.status !== 200 || !text.endsWith('OK'))
+    const uploadText = await uploadResponse.text();
+    if (uploadResponse.status !== 200 || !uploadText.endsWith('OK'))
       throw new ErrorNotification({
-        message: `Error: failed to upload backup to "${this.host.baseUrl}".`,
+        message: `Failed to upload backup to "${this.host.baseUrl}".`,
         verbose: {
           host: this.host.baseUrl,
-          status: response.status,
-          responseBody: text
+          status: uploadResponse.status,
+          responseBody: uploadText
         }
       });
 
     Log.info(chalk.green(`✔️ Backup uploaded to ${this.host.baseUrl}!`));
-    Log.verbose(`Result:\n${chalk.blue(text)}`);
+    Log.verbose(`Result:\n${chalk.blue(uploadText)}`);
+
+    if (Config.updateGravity) {
+      Log.info(chalk.yellow(`➡️ Updating gravity on ${this.host.baseUrl}...`));
+      const gravityUpdateResponse = await this.fetch(
+        `${this.host.baseUrl}/admin/scripts/pi-hole/php/gravity.sh.php`,
+        { method: 'GET' }
+      );
+
+      const updateText = (await gravityUpdateResponse.text())
+        .replaceAll('\ndata:', '')
+        .trim();
+      if (
+        gravityUpdateResponse.status !== 200 ||
+        !updateText.endsWith('Pi-hole blocking is enabled')
+      )
+        throw new ErrorNotification({
+          message: `Failed updating gravity on "${this.host.baseUrl}".`,
+          verbose: {
+            host: this.host.baseUrl,
+            status: gravityUpdateResponse.status,
+            eventStream: updateText
+          }
+        });
+
+      Log.info(chalk.green(`✔️ Gravity updated on ${this.host.baseUrl}!`));
+      Log.verbose(`Result:\n${chalk.blue(updateText)}`);
+    }
 
     return true;
   }
diff --git a/src/config.test.ts b/src/config.test.ts
index 7941fa6c..9295877f 100644
--- a/src/config.test.ts
+++ b/src/config.test.ts
@@ -238,6 +238,10 @@ describe('Config', () => {
     });
   });
 
+  describe('updateGravity', () => {
+    testToHaveDefaultAndOverride('updateGravity', true, 'UPDATE_GRAVITY');
+  });
+
   describe('verboseMode', () => {
     testToHaveDefaultAndOverride('verboseMode', false, 'VERBOSE');
   });
diff --git a/src/config.ts b/src/config.ts
index 2d2cdcb0..de45ad16 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -64,6 +64,10 @@ export class Config {
     return this._syncOptions;
   }
 
+  static get updateGravity(): boolean {
+    return process.env['UPDATE_GRAVITY'] !== 'false';
+  }
+
   static get verboseMode(): boolean {
     return process.env['VERBOSE'] === 'true';
   }