diff --git a/Net/src/IPAddress.cpp b/Net/src/IPAddress.cpp
index 1f7b7945d..69dc5ab3f 100644
--- a/Net/src/IPAddress.cpp
+++ b/Net/src/IPAddress.cpp
@@ -44,10 +44,14 @@ namespace Poco {
 namespace Net {
 
 
+#if !defined(_MSC_VER) || defined(__STDC__)
+// Go home MSVC, you're drunk...
+// See http://stackoverflow.com/questions/5899857/multiple-definition-error-for-static-const-class-members
 const IPAddress::Family IPAddress::IPv4;
 #if defined(POCO_HAVE_IPv6)
 const IPAddress::Family IPAddress::IPv6;
 #endif
+#endif
 
 
 IPAddress::IPAddress()
diff --git a/Net/src/SocketAddress.cpp b/Net/src/SocketAddress.cpp
index 72520be09..675edf319 100644
--- a/Net/src/SocketAddress.cpp
+++ b/Net/src/SocketAddress.cpp
@@ -58,6 +58,9 @@ struct AFLT
 //
 
 
+#if !defined(_MSC_VER) || defined(__STDC__)
+// Go home MSVC, you're drunk...
+// See http://stackoverflow.com/questions/5899857/multiple-definition-error-for-static-const-class-members
 const SocketAddress::Family SocketAddress::IPv4;
 #if defined(POCO_HAVE_IPv6)
 const SocketAddress::Family SocketAddress::IPv6;
@@ -65,6 +68,7 @@ const SocketAddress::Family SocketAddress::IPv6;
 #if defined(POCO_OS_FAMILY_UNIX)
 const SocketAddress::Family SocketAddress::UNIX_LOCAL;
 #endif
+#endif
 
 
 SocketAddress::SocketAddress()