diff --git a/samplecode/SampleCode.h b/samplecode/SampleCode.h
index ff660f2..fd3ed2a 100644
--- a/samplecode/SampleCode.h
+++ b/samplecode/SampleCode.h
@@ -20,7 +20,7 @@
 
 class SkViewRegister : SkNoncopyable {
 public:
-    SkViewRegister(SkViewFactory);
+    explicit SkViewRegister(SkViewFactory);
     
     static const SkViewRegister* Head() { return gHead; }