diff --git a/build/wxExtendDll.props b/build/wxExtendDll.props
index b328252..9f629f1 100644
--- a/build/wxExtendDll.props
+++ b/build/wxExtendDll.props
@@ -27,7 +27,7 @@
   <PropertyGroup />
   <ItemDefinitionGroup>
     <ClCompile>
-      <PreprocessorDefinitions>WXEXTEND_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WXMAKINGDLL_WXEXTEND;WXUSINGDLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
   </ItemDefinitionGroup>
   <ItemGroup>
diff --git a/include/wxex/common.h b/include/wxex/common.h
index 1f4ecd4..1ca4c28 100644
--- a/include/wxex/common.h
+++ b/include/wxex/common.h
@@ -48,9 +48,9 @@
 /// Public function calling convention
 ///
 #ifndef WXEXTEND_API
-#if defined(WXEXTEND_DLL)
+#if defined(WXMAKINGDLL_WXEXTEND)
 #define WXEXTEND_API      __declspec(dllexport)
-#elif defined(WXEXTEND_DLLIMP)
+#elif defined(WXUSINGDLL)
 #define WXEXTEND_API      __declspec(dllimport)
 #else
 #define WXEXTEND_API