diff --git a/build/win32/vs10/cogl.props b/build/win32/vs10/cogl.props
index 47d4245d3..9d78d62d3 100644
--- a/build/win32/vs10/cogl.props
+++ b/build/win32/vs10/cogl.props
@@ -9,7 +9,7 @@
     <DebugLibBuildDefines>_DEBUG;$(LibBuildDefines);COGL_GL_DEBUG;COGL_OBJECT_DEBUG;COGL_HANDLE_DEBUG</DebugLibBuildDefines>
     <CoglBuildDefines>G_LOG_DOMAIN="Cogl";COGL_HAS_WIN32_SUPPORT;COGL_BUILD_EXP;COGL_GL_LIBNAME="";COGL_LOCALEDIR="/some/random/dir"</CoglBuildDefines>
     <CoglPangoBuildDefines>G_LOG_DOMAIN="Cogl-Pango"</CoglPangoBuildDefines>
-    <TestProgDef>TESTS_DATADIR="../share/cogl-$(CoglApiVersion)/tests"</TestProgDef>
+    <TestProgDef>CLUTTER_COMPILATION;TESTS_DATADIR="../share/cogl-$(CoglApiVersion)/tests"</TestProgDef>
     <CopyDir>$(GlibEtcInstallRoot)</CopyDir>
     <PreBuildCmd>
 if exist ..\..\..\config.h goto DONE_CONFIG_H
diff --git a/build/win32/vs9/cogl.vsprops b/build/win32/vs9/cogl.vsprops
index bd4c39423..d7b784b86 100644
--- a/build/win32/vs9/cogl.vsprops
+++ b/build/win32/vs9/cogl.vsprops
@@ -52,7 +52,7 @@
 	/>
 	<UserMacro
 		Name="TestProgDef"
-		Value="TESTS_DATADIR=\&quot;../share/cogl-$(CoglApiVersion)/tests\&quot;"
+		Value="CLUTTER_COMPILATION;TESTS_DATADIR=\&quot;../share/cogl-$(CoglApiVersion)/tests\&quot;"
 	/>
 	<UserMacro
 		Name="PreBuildCmd"