diff --git a/include/wx/msw/missing.h b/include/wx/msw/missing.h
index f42a31ca1f..8018403dda 100644
--- a/include/wx/msw/missing.h
+++ b/include/wx/msw/missing.h
@@ -516,57 +516,136 @@ typedef struct
 
 #endif
 
-// Various definitions are missing from mingw
-// Used by webview_ie.cpp
+//Various defines that will be needed by mingw and possibly VC++6
+//Used by the webview library
 #ifdef __MINGW32__
 typedef enum CommandStateChangeConstants {
     CSC_UPDATECOMMANDS = (int) 0xFFFFFFFF,
     CSC_NAVIGATEFORWARD = 0x1,
     CSC_NAVIGATEBACK = 0x2
 } CommandStateChangeConstants;
-
-#define DISPID_COMMANDSTATECHANGE 105
-#define DISPID_NAVIGATECOMPLETE2 252
-#define DISPID_NAVIGATEERROR 271
-#define DISPID_NEWWINDOW3 273
-#define INET_E_ERROR_FIRST 0x800C0002L
-#define INET_E_INVALID_URL 0x800C0002L
-#define INET_E_NO_SESSION 0x800C0003L
-#define INET_E_CANNOT_CONNECT 0x800C0004L
-#define INET_E_RESOURCE_NOT_FOUND 0x800C0005L
-#define INET_E_OBJECT_NOT_FOUND 0x800C0006L
-#define INET_E_DATA_NOT_AVAILABLE 0x800C0007L
-#define INET_E_DOWNLOAD_FAILURE 0x800C0008L
-#define INET_E_AUTHENTICATION_REQUIRED 0x800C0009L
-#define INET_E_NO_VALID_MEDIA 0x800C000AL
-#define INET_E_CONNECTION_TIMEOUT 0x800C000BL
-#define INET_E_INVALID_REQUEST 0x800C000CL
-#define INET_E_UNKNOWN_PROTOCOL 0x800C000DL
-#define INET_E_SECURITY_PROBLEM 0x800C000EL
-#define INET_E_CANNOT_LOAD_DATA 0x800C000FL
-#define INET_E_CANNOT_INSTANTIATE_OBJECT 0x800C0010L
-#define INET_E_QUERYOPTION_UNKNOWN 0x800C0013L
-#define INET_E_REDIRECT_FAILED 0x800C0014L
-#define INET_E_REDIRECT_TO_DIR 0x800C0015L
-#define INET_E_CANNOT_LOCK_REQUEST 0x800C0016L
-#define INET_E_USE_EXTEND_BINDING 0x800C0017L
-#define INET_E_TERMINATED_BIND 0x800C0018L
-#define INET_E_INVALID_CERTIFICATE 0x800C0019L
-#define INET_E_CODE_DOWNLOAD_DECLINED 0x800C0100L
-#define INET_E_RESULT_DISPATCHED 0x800C0200L
-#define INET_E_CANNOT_REPLACE_SFP_FILE 0x800C0300L
-#define INET_E_CODE_INSTALL_BLOCKED_BY_HASH_POLICY 0x800C0500L
-#define INET_E_CODE_INSTALL_SUPPRESSED 0x800C0400L
-
-#define REFRESH_NORMAL 0
-#define REFRESH_COMPLETELY 3
 #endif
 
-// For Visual C++ 6 and MinGW32. Used by webview_ie.cpp
+#ifndef DISPID_COMMANDSTATECHANGE
+#define DISPID_COMMANDSTATECHANGE 105
+#endif
+
+#ifndef DISPID_NAVIGATECOMPLETE2
+#define DISPID_NAVIGATECOMPLETE2 252
+#endif
+
+#ifndef DISPID_NAVIGATEERROR
+#define DISPID_NAVIGATEERROR 271
+#endif
+
+#ifndef DISPID_NEWWINDOW3
+#define DISPID_NEWWINDOW3 273
+#endif
+
+#ifndef INET_E_ERROR_FIRST
+#define INET_E_ERROR_FIRST 0x800C0002L
+#endif
+
+#ifndef INET_E_INVALID_URL
+#define INET_E_INVALID_URL 0x800C0002L
+#endif
+
+#ifndef INET_E_NO_SESSION
+#define INET_E_NO_SESSION 0x800C0003L
+#endif
+
+#ifndef INET_E_CANNOT_CONNECT
+#define INET_E_CANNOT_CONNECT 0x800C0004L
+#endif
+
+#ifndef INET_E_RESOURCE_NOT_FOUND
+#define INET_E_RESOURCE_NOT_FOUND 0x800C0005L
+#endif
+
+#ifndef INET_E_OBJECT_NOT_FOUND
+#define INET_E_OBJECT_NOT_FOUND 0x800C0006L
+#endif
+
+#ifndef INET_E_DATA_NOT_AVAILABLE
+#define INET_E_DATA_NOT_AVAILABLE 0x800C0007L
+#endif
+
+#ifndef INET_E_DOWNLOAD_FAILURE
+#define INET_E_DOWNLOAD_FAILURE 0x800C0008L
+#endif
+
+#ifndef INET_E_AUTHENTICATION_REQUIRED
+#define INET_E_AUTHENTICATION_REQUIRED 0x800C0009L
+#endif
+
+#ifndef INET_E_NO_VALID_MEDIA
+#define INET_E_NO_VALID_MEDIA 0x800C000AL
+#endif
+
+#ifndef INET_E_CONNECTION_TIMEOUT
+#define INET_E_CONNECTION_TIMEOUT 0x800C000BL
+#endif
+
+#ifndef INET_E_INVALID_REQUEST
+#define INET_E_INVALID_REQUEST 0x800C000CL
+#endif
+
+#ifndef INET_E_UNKNOWN_PROTOCOL
+#define INET_E_UNKNOWN_PROTOCOL 0x800C000DL
+#endif
+
+#ifndef INET_E_SECURITY_PROBLEM
+#define INET_E_SECURITY_PROBLEM 0x800C000EL
+#endif
+
+#ifndef INET_E_CANNOT_LOAD_DATA
+#define INET_E_CANNOT_LOAD_DATA 0x800C000FL
+#endif
+
+#ifndef INET_E_CANNOT_INSTANTIATE_OBJECT
+#define INET_E_CANNOT_INSTANTIATE_OBJECT 0x800C0010L
+#endif
+
+#ifndef INET_E_QUERYOPTION_UNKNOWN
+#define INET_E_QUERYOPTION_UNKNOWN 0x800C0013L
+#endif
+
+#ifndef INET_E_REDIRECT_FAILED
+#define INET_E_REDIRECT_FAILED 0x800C0014L
+#endif
+
+#ifndef INET_E_REDIRECT_TO_DIR
+#define INET_E_REDIRECT_TO_DIR 0x800C0015L
+#endif
+
+#ifndef INET_E_CANNOT_LOCK_REQUEST
+#define INET_E_CANNOT_LOCK_REQUEST 0x800C0016L
+#endif
+
+#ifndef INET_E_USE_EXTEND_BINDING
+#define INET_E_USE_EXTEND_BINDING 0x800C0017L
+#endif
+
+#ifndef INET_E_TERMINATED_BIND
+#define INET_E_TERMINATED_BIND 0x800C0018L
+#endif
+
 #ifndef INET_E_INVALID_CERTIFICATE
 #define INET_E_INVALID_CERTIFICATE 0x800C0019L
 #endif
 
+#ifndef INET_E_CODE_DOWNLOAD_DECLINED
+#define INET_E_CODE_DOWNLOAD_DECLINED 0x800C0100L
+#endif
+
+#ifndef INET_E_RESULT_DISPATCHED
+#define INET_E_RESULT_DISPATCHED 0x800C0200L
+#endif
+
+#ifndef INET_E_CANNOT_REPLACE_SFP_FILE
+#define INET_E_CANNOT_REPLACE_SFP_FILE 0x800C0300L
+#endif
+
 #ifndef INET_E_CODE_INSTALL_BLOCKED_BY_HASH_POLICY
 #define INET_E_CODE_INSTALL_BLOCKED_BY_HASH_POLICY 0x800C0500L
 #endif
@@ -575,10 +654,6 @@ typedef enum CommandStateChangeConstants {
 #define INET_E_CODE_INSTALL_SUPPRESSED 0x800C0400L
 #endif
 
-#ifndef DISPID_NEWWINDOW3
-#define DISPID_NEWWINDOW3 273
-#endif
-
 //We need to check if we are using MinGW which doesn't inlcude the urlmon
 //defintions as opposed to MinGW-64 which does
 
@@ -590,6 +665,9 @@ typedef enum CommandStateChangeConstants {
 //Used by webview
 #if defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR)
 
+#define REFRESH_NORMAL 0
+#define REFRESH_COMPLETELY 3
+
 EXTERN_C const IID CLSID_FileProtocol;
 
 DEFINE_GUID(IID_IInternetProtocolRoot,0x79eac9e3,0xbaf9,0x11ce,0x8c,0x82,0,0xaa,0,0x4b,0xa9,0xb);