diff --git a/package.json b/package.json
index 54748967ea..095e5b7b02 100644
--- a/package.json
+++ b/package.json
@@ -157,7 +157,7 @@
     "@react-spring/web": "10.0.3",
     "@react-types/shared": "3.33.1",
     "@signalapp/minimask": "1.0.1",
-    "@signalapp/mock-server": "18.3.0",
+    "@signalapp/mock-server": "19.0.0",
     "@signalapp/quill-cjs": "2.1.2",
     "@storybook/addon-a11y": "8.4.4",
     "@storybook/addon-actions": "8.4.4",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 2b045b8626..d65af6663f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -198,8 +198,8 @@ importers:
         specifier: 1.0.1
         version: 1.0.1
       '@signalapp/mock-server':
-        specifier: 18.3.0
-        version: 18.3.0(bufferutil@4.0.9)(utf-8-validate@5.0.10)
+        specifier: 19.0.0
+        version: 19.0.0(bufferutil@4.0.9)(utf-8-validate@5.0.10)
       '@signalapp/quill-cjs':
         specifier: 2.1.2
         version: 2.1.2
@@ -3720,8 +3720,8 @@ packages:
   '@signalapp/minimask@1.0.1':
     resolution: {integrity: sha512-QAwo0joA60urTNbW9RIz6vLKQjy+jdVtH7cvY0wD9PVooD46MAjE40MLssp4xUJrph91n2XvtJ3pbEUDrmT2AA==}
 
-  '@signalapp/mock-server@18.3.0':
-    resolution: {integrity: sha512-IDqt4YsyoN1myDZYeaMh42Sfx310F0APT/9hggrLhqYwOto43AIZPXaCzG2Cjbh3n9wCPVrtTGxO3Q74/BdEWg==}
+  '@signalapp/mock-server@19.0.0':
+    resolution: {integrity: sha512-r6AMw6oGv6rwsbiyOMrxojzqG+q873cPl5pddnn07V2HlW7O1PyHsVKgyemTnV8I0EK4zt2pfSo/FC2QotB9FQ==}
 
   '@signalapp/parchment-cjs@3.0.1':
     resolution: {integrity: sha512-hSBMQ1M7wE4GcC8ZeNtvpJF+DAJg3eIRRf1SiHS3I3Algav/sgJJNm6HIYm6muHuK7IJmuEjkL3ILSXgmu0RfQ==}
@@ -14190,7 +14190,7 @@ snapshots:
 
   '@signalapp/minimask@1.0.1': {}
 
-  '@signalapp/mock-server@18.3.0(bufferutil@4.0.9)(utf-8-validate@5.0.10)':
+  '@signalapp/mock-server@19.0.0(bufferutil@4.0.9)(utf-8-validate@5.0.10)':
     dependencies:
       '@indutny/parallel-prettier': 3.0.0(prettier@3.7.4)
       '@indutny/protopiler': 3.2.1
diff --git a/ts/textsecure/preconnect.preload.ts b/ts/textsecure/preconnect.preload.ts
index 79fc3443b3..8de2865e69 100644
--- a/ts/textsecure/preconnect.preload.ts
+++ b/ts/textsecure/preconnect.preload.ts
@@ -42,6 +42,7 @@ function resolveLibsignalNet(
       TESTING_localServer_svr2Port: DISCARD_PORT,
       TESTING_localServer_svrBPort: DISCARD_PORT,
       TESTING_localServer_rootCertificateDer: pemToDer(certificateAuthority),
+      TESTING_localServer_httpVersion: 2,
     });
   }