diff --git a/include/ethernetII.h b/include/ethernetII.h
index 3ac5e75..80821f3 100644
--- a/include/ethernetII.h
+++ b/include/ethernetII.h
@@ -45,7 +45,7 @@ namespace Tins {
         /**
          * \brief Ethernet II hardware address size.
          */
-        static const uint32_t ADDR_SIZE = 6;
+        static const unsigned ADDR_SIZE = 6;
 
         /**
          * \brief Constructor for creating an ethernet PDU
@@ -217,4 +217,5 @@ namespace Tins {
 
 };
 
+
 #endif
diff --git a/src/ethernetII.cpp b/src/ethernetII.cpp
index 31f658c..18e5e5c 100644
--- a/src/ethernetII.cpp
+++ b/src/ethernetII.cpp
@@ -33,7 +33,7 @@
 #include "utils.h"
 
 const uint8_t* Tins::EthernetII::BROADCAST = (const uint8_t*)"\xff\xff\xff\xff\xff\xff";
-//const uint32_t Tins::EthernetII::ADDR_SIZE = 6;
+const uint32_t Tins::EthernetII::ADDR_SIZE;
 
 Tins::EthernetII::EthernetII(const std::string& iface, const uint8_t* dst_hw_addr, const uint8_t* src_hw_addr, PDU* child) throw (std::runtime_error) : PDU(ETHERTYPE_IP, child) {
     memset(&_eth, 0, sizeof(ethhdr));