diff --git a/runtime/src/main/java/org/capnproto/ClientHook.java b/runtime/src/main/java/org/capnproto/ClientHook.java
index b3a30c6..573c072 100644
--- a/runtime/src/main/java/org/capnproto/ClientHook.java
+++ b/runtime/src/main/java/org/capnproto/ClientHook.java
@@ -77,10 +77,10 @@ public interface ClientHook {
     }
 
     final class VoidPromiseAndPipeline {
-        public final CompletionStage<java.lang.Void> promise;
+        public final CompletableFuture<java.lang.Void> promise;
         public final PipelineHook pipeline;
 
-        VoidPromiseAndPipeline(CompletionStage<java.lang.Void> promise, PipelineHook pipeline) {
+        VoidPromiseAndPipeline(CompletableFuture<java.lang.Void> promise, PipelineHook pipeline) {
             this.promise = promise;
             this.pipeline = pipeline;
         }
diff --git a/runtime/src/main/java/org/capnproto/RemotePromise.java b/runtime/src/main/java/org/capnproto/RemotePromise.java
index 1550004..8cf7bb9 100644
--- a/runtime/src/main/java/org/capnproto/RemotePromise.java
+++ b/runtime/src/main/java/org/capnproto/RemotePromise.java
@@ -1,14 +1,15 @@
 package org.capnproto;
 
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionStage;
 
 public class RemotePromise<Results>
         extends CompletableFutureWrapper<Results> {
 
-    final CompletionStage<Response<Results>> response;
+    final CompletableFuture<Response<Results>> response;
     final PipelineHook hook;
 
-    RemotePromise(CompletionStage<Response<Results>> promise,
+    RemotePromise(CompletableFuture<Response<Results>> promise,
                   PipelineHook hook) {
         super(promise.thenApply(response -> response.getResults()));
         this.response = promise;