diff --git a/compiler/src/test/scala/org/capnproto/EncodingSuite.scala b/compiler/src/test/scala/org/capnproto/EncodingSuite.scala
index 264ac5a..1c05e17 100644
--- a/compiler/src/test/scala/org/capnproto/EncodingSuite.scala
+++ b/compiler/src/test/scala/org/capnproto/EncodingSuite.scala
@@ -563,6 +563,32 @@ class EncodingSuite extends FunSuite {
     }
   }
 
+  test("StructSetters") {
+    val builder = new MessageBuilder()
+    val root = builder.initRoot(TestAllTypes.factory)
+    TestUtil.initTestMessage(root)
+
+    {
+      val builder2 = new MessageBuilder()
+      builder2.setRoot(TestAllTypes.factory, root.asReader())
+      TestUtil.checkTestMessage(builder2.getRoot(TestAllTypes.factory))
+    }
+
+    {
+      val builder2 = new MessageBuilder()
+      val root2 = builder2.getRoot(TestAllTypes.factory)
+      root2.setStructField(root.asReader())
+      TestUtil.checkTestMessage(root2.getStructField())
+    }
+
+    {
+      val builder2 = new MessageBuilder()
+      val root2 = builder2.getRoot(TestAnyPointer.factory)
+      root2.getAnyPointerField().setAs(TestAllTypes.factory, root.asReader())
+      TestUtil.checkTestMessage(root2.getAnyPointerField.getAs(TestAllTypes.factory))
+    }
+  }
+
 
   // to debug, do this:
   //Serialize.write((new java.io.FileOutputStream("/Users/dwrensha/Desktop/test.dat")).getChannel(),
diff --git a/runtime/src/main/java/org/capnproto/MessageBuilder.java b/runtime/src/main/java/org/capnproto/MessageBuilder.java
index d8ec266..e384734 100644
--- a/runtime/src/main/java/org/capnproto/MessageBuilder.java
+++ b/runtime/src/main/java/org/capnproto/MessageBuilder.java
@@ -40,11 +40,7 @@ public final class MessageBuilder {
                                       allocationStrategy);
     }
 
-    public <T> T getRoot(StructBuilder.Factory<T> factory) {
-        throw new Error("unimplemented");
-    }
-
-    public <T> T initRoot(FromPointerBuilder<T> factory) {
+    private AnyPointer.Builder getRootInternal() {
         SegmentBuilder rootSegment = this.arena.segments.get(0);
         if (rootSegment.currentSize() == 0) {
             int location = rootSegment.allocate(1);
@@ -54,12 +50,24 @@ public final class MessageBuilder {
             if (location != 0) {
                 throw new Error("First allocated word of new segment was not at offset 0");
             }
-           return factory.initFromPointerBuilder(rootSegment, location, 0);
+            return new AnyPointer.Builder(rootSegment, location);
         } else {
-           return factory.initFromPointerBuilder(rootSegment, 0, 0);
+            return new AnyPointer.Builder(rootSegment, 0);
         }
     }
 
+    public <T> T getRoot(FromPointerBuilder<T> factory) {
+        return this.getRootInternal().getAs(factory);
+    }
+
+    public <T, U> void setRoot(SetPointerBuilder<T, U> factory, U reader) {
+        this.getRootInternal().setAs(factory, reader);
+    }
+
+    public <T> T initRoot(FromPointerBuilder<T> factory) {
+        return this.getRootInternal().initAs(factory);
+    }
+
     public final java.nio.ByteBuffer[] getSegmentsForOutput() {
         return this.arena.getSegmentsForOutput();
     }