diff --git a/snapshot/src/core/config.ts b/snapshot/src/core/config.ts
index bf783ab..1a94d60 100644
--- a/snapshot/src/core/config.ts
+++ b/snapshot/src/core/config.ts
@@ -11,5 +11,8 @@ export function loadConfig(): Config {
     throw new Error('AUTHOR_PUBKEY_HEX muss 64 hex chars sein')
   }
   if (!bootstrapRelay) throw new Error('BOOTSTRAP_RELAY fehlt in env')
+  if (!bootstrapRelay.startsWith('wss://') && !bootstrapRelay.startsWith('ws://')) {
+    throw new Error('BOOTSTRAP_RELAY muss eine wss:// (oder ws://) URL sein')
+  }
   return { authorPubkeyHex, bootstrapRelay }
 }
diff --git a/snapshot/tests/config.test.ts b/snapshot/tests/config.test.ts
index f34d6bc..e1f5fcf 100644
--- a/snapshot/tests/config.test.ts
+++ b/snapshot/tests/config.test.ts
@@ -20,3 +20,9 @@ Deno.test('loadConfig wirft bei ungueltigem hex', () => {
   Deno.env.set('BOOTSTRAP_RELAY', 'wss://relay.primal.net')
   assertThrows(() => loadConfig(), Error, '64 hex')
 })
+
+Deno.test('loadConfig wirft bei ungueltigem BOOTSTRAP_RELAY (kein wss://)', () => {
+  Deno.env.set('AUTHOR_PUBKEY_HEX', '4fa5d1c413e2b45e10d40bf3562ab701a5331206e359c90baae0e99bfd6c6e41')
+  Deno.env.set('BOOTSTRAP_RELAY', 'http://relay.example.com')
+  assertThrows(() => loadConfig(), Error, 'wss://')
+})