diff --git a/runtime/jdwp/jdwp_priv.h b/runtime/jdwp/jdwp_priv.h
index ab89339..557632c 100644
--- a/runtime/jdwp/jdwp_priv.h
+++ b/runtime/jdwp/jdwp_priv.h
@@ -53,7 +53,7 @@
  */
 class JdwpNetStateBase {
  public:
-  JdwpNetStateBase(JdwpState*);
+  explicit JdwpNetStateBase(JdwpState*);
   virtual ~JdwpNetStateBase();
 
   virtual bool Accept() = 0;