diff --git a/src/Squidex/Config/Domain/PubSubModule.cs b/src/Squidex/Config/Domain/PubSubModule.cs
index c731e71a5..ca6195448 100644
--- a/src/Squidex/Config/Domain/PubSubModule.cs
+++ b/src/Squidex/Config/Domain/PubSubModule.cs
@@ -42,7 +42,7 @@ namespace Squidex.Config.Domain
 
                 if (string.IsNullOrWhiteSpace(configuration))
                 {
-                    throw new ConfigurationException("Configure PubSub Redis configuration with pubSub:redis:configuration'.");
+                    throw new ConfigurationException("Configure PubSub Redis configuration with 'pubSub:redis:configuration'.");
                 }
 
                 builder.Register(c => Singletons<IConnectionMultiplexer>.GetOrAdd(configuration, s => ConnectionMultiplexer.Connect(s)))