diff --git a/Source/MQTTnet/Server/IMqttServerCertificateCredentials.cs b/Source/MQTTnet/Server/IMqttServerCertificateCredentials.cs
new file mode 100644
index 0000000..3f5fe0e
--- /dev/null
+++ b/Source/MQTTnet/Server/IMqttServerCertificateCredentials.cs
@@ -0,0 +1,4 @@
+public interface IMqttServerCertificateCredentials
+{
+    string Password { get; }
+}
diff --git a/Source/MQTTnet/Server/IMqttServerCredentials.cs b/Source/MQTTnet/Server/IMqttServerCredentials.cs
deleted file mode 100644
index 5e75be9..0000000
--- a/Source/MQTTnet/Server/IMqttServerCredentials.cs
+++ /dev/null
@@ -1,6 +0,0 @@
-using System;
-
-public interface IMqttServerCredentials
-{
-    String Password { get; }
-}
diff --git a/Source/MQTTnet/Server/MqttServerCertificateCredentials.cs b/Source/MQTTnet/Server/MqttServerCertificateCredentials.cs
new file mode 100644
index 0000000..05b6c5f
--- /dev/null
+++ b/Source/MQTTnet/Server/MqttServerCertificateCredentials.cs
@@ -0,0 +1,7 @@
+namespace MQTTnet.Server
+{
+    public class MqttServerCertificateCredentials : IMqttServerCertificateCredentials
+    {
+        public string Password { get; set; }
+    }
+}
diff --git a/Source/MQTTnet/Server/MqttServerOptionsBuilder.cs b/Source/MQTTnet/Server/MqttServerOptionsBuilder.cs
index 5991e7d..c25af84 100644
--- a/Source/MQTTnet/Server/MqttServerOptionsBuilder.cs
+++ b/Source/MQTTnet/Server/MqttServerOptionsBuilder.cs
@@ -82,7 +82,7 @@ namespace MQTTnet.Server
             return this;
         }
 
-        public MqttServerOptionsBuilder WithEncryptionCertificate(byte[] value, IMqttServerCredentials credentials = null)
+        public MqttServerOptionsBuilder WithEncryptionCertificate(byte[] value, IMqttServerCertificateCredentials credentials = null)
         {
             _options.TlsEndpointOptions.Certificate = value;
             _options.TlsEndpointOptions.CertificateCredentials = credentials;
diff --git a/Source/MQTTnet/Server/MqttServerTlsTcpEndpointOptions.cs b/Source/MQTTnet/Server/MqttServerTlsTcpEndpointOptions.cs
index e92d987..9bf325b 100644
--- a/Source/MQTTnet/Server/MqttServerTlsTcpEndpointOptions.cs
+++ b/Source/MQTTnet/Server/MqttServerTlsTcpEndpointOptions.cs
@@ -12,7 +12,7 @@ namespace MQTTnet.Server
 
         public byte[] Certificate { get; set; }
 
-        public IMqttServerCredentials CertificateCredentials { get; set; }
+        public IMqttServerCertificateCredentials CertificateCredentials { get; set; }
 
         public bool ClientCertificateRequired { get; set; }