diff --git a/src/address/address.h b/src/address/address.h
index e8ab35c8f..ffd32fc5e 100644
--- a/src/address/address.h
+++ b/src/address/address.h
@@ -36,7 +36,7 @@ class LINPHONE_PUBLIC Address : public ClonableObject {
 	friend class ClientGroupChatRoomPrivate;
 
 public:
-	Address (const std::string &address = "");
+	explicit Address (const std::string &address = "");
 	Address (const Address &src);
 	~Address ();
 
diff --git a/src/logger/logger.h b/src/logger/logger.h
index 2a904e85c..5c8a9ea19 100644
--- a/src/logger/logger.h
+++ b/src/logger/logger.h
@@ -40,7 +40,7 @@ public:
 		Fatal
 	};
 
-	Logger (Level level);
+	explicit Logger (Level level);
 	~Logger ();
 
 	std::ostringstream &getOutput ();