diff --git a/cli/src/__tests__/allowed-hostname.test.ts b/cli/src/__tests__/allowed-hostname.test.ts
index 92dfbf42..572689c4 100644
--- a/cli/src/__tests__/allowed-hostname.test.ts
+++ b/cli/src/__tests__/allowed-hostname.test.ts
@@ -42,6 +42,7 @@ function writeBaseConfig(configPath: string) {
     },
     auth: {
       baseUrlMode: "auto",
+      disableSignUp: false,
     },
     storage: {
       provider: "local_disk",
diff --git a/cli/src/commands/configure.ts b/cli/src/commands/configure.ts
index d072fee9..969ead97 100644
--- a/cli/src/commands/configure.ts
+++ b/cli/src/commands/configure.ts
@@ -61,6 +61,7 @@ function defaultConfig(): PaperclipConfig {
     },
     auth: {
       baseUrlMode: "auto",
+      disableSignUp: false,
     },
     storage: defaultStorageConfig(),
     secrets: defaultSecretsConfig(),
diff --git a/cli/src/commands/onboard.ts b/cli/src/commands/onboard.ts
index 0e70d9cf..e3f17001 100644
--- a/cli/src/commands/onboard.ts
+++ b/cli/src/commands/onboard.ts
@@ -185,6 +185,7 @@ function quickstartDefaultsFromEnv(): {
     },
     auth: {
       baseUrlMode: authBaseUrlMode,
+      disableSignUp: false,
       ...(authPublicBaseUrl ? { publicBaseUrl: authPublicBaseUrl } : {}),
     },
     storage: {
diff --git a/cli/src/prompts/server.ts b/cli/src/prompts/server.ts
index c2ab4218..00611560 100644
--- a/cli/src/prompts/server.ts
+++ b/cli/src/prompts/server.ts
@@ -113,7 +113,7 @@ export async function promptServer(opts?: {
   }
 
   const port = Number(portStr) || 3100;
-  let auth: AuthConfig = { baseUrlMode: "auto" };
+  let auth: AuthConfig = { baseUrlMode: "auto", disableSignUp: false };
   if (deploymentMode === "authenticated" && exposure === "public") {
     const urlInput = await p.text({
       message: "Public base URL",
@@ -139,11 +139,13 @@ export async function promptServer(opts?: {
     }
     auth = {
       baseUrlMode: "explicit",
+      disableSignUp: false,
       publicBaseUrl: urlInput.trim().replace(/\/+$/, ""),
     };
   } else if (currentAuth?.baseUrlMode === "explicit" && currentAuth.publicBaseUrl) {
     auth = {
       baseUrlMode: "explicit",
+      disableSignUp: false,
       publicBaseUrl: currentAuth.publicBaseUrl,
     };
   }