diff --git a/coap-core/src/main/java/com/mbed/coap/server/CoapServerBuilder.java b/coap-core/src/main/java/com/mbed/coap/server/CoapServerBuilder.java
index 08695fed..38134387 100644
--- a/coap-core/src/main/java/com/mbed/coap/server/CoapServerBuilder.java
+++ b/coap-core/src/main/java/com/mbed/coap/server/CoapServerBuilder.java
@@ -80,7 +80,7 @@ public final class CoapServerBuilder {
     private int maxQueueSize = 100;
     private Filter.SimpleFilter<CoapRequest, CoapResponse> outboundFilter = Filter.identity();
     private Filter.SimpleFilter<CoapRequest, CoapResponse> routeFilter = Filter.identity();
-    private Filter<CoapRequest, CoapResponse, CoapRequest, CoapResponse> inboundRequestFilter = Filter.identity();
+    private Filter.SimpleFilter<CoapRequest, CoapResponse> inboundRequestFilter = Filter.identity();
     private NotificationsReceiver notificationsReceiver = NotificationsReceiver.REJECT_ALL;
     private ObservationsStore observationStore = ObservationsStore.ALWAYS_EMPTY;
     private RequestTagSupplier requestTagSupplier = RequestTagSupplier.createSequential();
@@ -120,7 +120,7 @@ public CoapServerBuilder routeFilter(Filter.SimpleFilter<CoapRequest, CoapRespon
         return this;
     }
 
-    public CoapServerBuilder inboundRequestFilter(Filter<CoapRequest, CoapResponse, CoapRequest, CoapResponse> inboundRequestFilter) {
+    public CoapServerBuilder inboundRequestFilter(Filter.SimpleFilter<CoapRequest, CoapResponse> inboundRequestFilter) {
         this.inboundRequestFilter = requireNonNull(inboundRequestFilter);
         return this;
     }