diff --git a/compiler/dex/growable_array.h b/compiler/dex/growable_array.h
index 6ab0f16..6d26bc2 100644
--- a/compiler/dex/growable_array.h
+++ b/compiler/dex/growable_array.h
@@ -49,7 +49,7 @@
 
     class Iterator {
       public:
-        Iterator(GrowableArray* g_list)
+        explicit Iterator(GrowableArray* g_list)
           : idx_(0),
             g_list_(g_list) {};