diff --git a/bind/java/doc.go b/bind/java/doc.go
new file mode 100644
index 0000000..0002208
--- /dev/null
+++ b/bind/java/doc.go
@@ -0,0 +1,6 @@
+// Package java implements the Java language bindings.
+//
+// See the design document (http://golang.org/s/gobind).
+//
+// Currently, this works only for android.
+package java
diff --git a/example/libhellojni/hello.c b/example/libhellojni/hello.c
index 6bf27e3..d96b405 100644
--- a/example/libhellojni/hello.c
+++ b/example/libhellojni/hello.c
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build android
+
 // See main.go for commentary.
 
 #include <android/log.h>
diff --git a/example/libhellojni/hello.go b/example/libhellojni/hello.go
index 9e8b5a1..666666d 100644
--- a/example/libhellojni/hello.go
+++ b/example/libhellojni/hello.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build android
+
 package main
 
 // #cgo LDFLAGS: -llog
diff --git a/example/libhellojni/main.go b/example/libhellojni/main.go
index fd6a218..79a16b4 100644
--- a/example/libhellojni/main.go
+++ b/example/libhellojni/main.go
@@ -26,5 +26,5 @@ package main
 import "golang.org/x/mobile/app"
 
 func main() {
-	app.Run()
+	app.Run(app.Callbacks{})
 }