diff --git a/libs/freetdm/msvc/freetdm.2008.vcproj b/libs/freetdm/msvc/freetdm.2008.vcproj
index 0539ff3f42..2619f23d74 100644
--- a/libs/freetdm/msvc/freetdm.2008.vcproj
+++ b/libs/freetdm/msvc/freetdm.2008.vcproj
@@ -46,7 +46,7 @@
 				Name="VCCLCompilerTool"
 				Optimization="0"
 				AdditionalIncludeDirectories="../src/include;../src/include/private;../src/isdn/include"
-				PreprocessorDefinitions="WIN32;_DEBUG;_LIB;_CRT_SECURE_NO_WARNINGS;FREETDM_EXPORTS;TELETONE_EXPORTS"
+				PreprocessorDefinitions="WIN32;_DEBUG;_LIB;_CRT_SECURE_NO_WARNINGS;FREETDM_EXPORTS;TELETONE_EXPORTS;_WIN32_WINNT=0x0501"
 				MinimalRebuild="true"
 				BasicRuntimeChecks="3"
 				RuntimeLibrary="3"