diff --git a/launcher/afterSignMac.js b/launcher/afterSignMac.js
new file mode 100644
index 000000000..91df3b4ce
--- /dev/null
+++ b/launcher/afterSignMac.js
@@ -0,0 +1,26 @@
+const { execSync } = require("child_process");
+const path = require("path");
+
+// electron-builder v26 no longer re-signs bundled frameworks when no certificate is
+// provided. The Electron Framework ships pre-signed with the Electron project's Apple
+// Team ID, causing macOS 26+ to reject the load because the main executable has no
+// Team ID. Re-sign everything with ad-hoc ("-") so all binaries share a consistent
+// (empty) Team ID and dyld's validation passes.
+//
+// This must be afterSign (not afterPack) for --universal builds: afterPack fires once
+// per arch on the temporary per-arch outputs before @electron/universal merges them.
+// Re-signing those temps makes CodeResources differ between architectures, causing the
+// merge to fail with "non-binary files have different SHAs". afterSign fires once on
+// the final merged universal .app, after the merge succeeds.
+exports.default = async function afterSignMac(context) {
+  if (context.electronPlatformName !== "darwin") return;
+
+  const appPath = path.join(context.appOutDir, `${context.packager.appInfo.productFilename}.app`);
+
+  console.log(`[afterSignMac] Ad-hoc re-signing for macOS 26+ Team ID compatibility:`);
+  console.log(`[afterSignMac] ${appPath}`);
+
+  execSync(`codesign --force --deep --sign - "${appPath}"`, { stdio: "inherit" });
+
+  console.log(`[afterSignMac] Done.`);
+};
diff --git a/launcher/vue.config.js b/launcher/vue.config.js
index 4c6b236d2..bef4fdf0f 100755
--- a/launcher/vue.config.js
+++ b/launcher/vue.config.js
@@ -12,8 +12,11 @@ module.exports = {
         },
         appId: "com.stereum.launcher",
         productName: "Stereum-Launcher",
-        ...(shouldNotarize ? { afterSign: "@sapien99/vue-cli-plugin-electron-builder-notarize" } : {}),
-        ...(!isSigned ? { afterPack: "./afterPackMac.js" } : {}),
+        ...(shouldNotarize
+          ? { afterSign: "@sapien99/vue-cli-plugin-electron-builder-notarize" }
+          : !isSigned
+            ? { afterSign: "./afterSignMac.js" }
+            : {}),
         buildDependenciesFromSource: false,
         nodeGypRebuild: false,
         npmRebuild: false,