diff --git a/libs/win32/howl/libhowl.2008.vcproj b/libs/win32/howl/libhowl.2008.vcproj
index 849a564ce5..40349ac9db 100644
--- a/libs/win32/howl/libhowl.2008.vcproj
+++ b/libs/win32/howl/libhowl.2008.vcproj
@@ -48,7 +48,6 @@
 				RuntimeLibrary="3"
 				UsePrecompiledHeader="0"
 				WarningLevel="0"
-				Detect64BitPortabilityProblems="true"
 				DebugInformationFormat="3"
 				CallingConvention="2"
 			/>
@@ -115,7 +114,6 @@
 				EnableFunctionLevelLinking="true"
 				UsePrecompiledHeader="0"
 				WarningLevel="0"
-				Detect64BitPortabilityProblems="true"
 				DebugInformationFormat="3"
 				CallingConvention="2"
 			/>
diff --git a/libs/win32/iksemel/iksemel.2008.vcproj b/libs/win32/iksemel/iksemel.2008.vcproj
index 09ea333c1a..056dac44a7 100644
--- a/libs/win32/iksemel/iksemel.2008.vcproj
+++ b/libs/win32/iksemel/iksemel.2008.vcproj
@@ -48,7 +48,6 @@
 				RuntimeLibrary="3"
 				UsePrecompiledHeader="0"
 				WarningLevel="0"
-				Detect64BitPortabilityProblems="true"
 				DebugInformationFormat="3"
 			/>
 			<Tool
@@ -109,7 +108,6 @@
 				RuntimeLibrary="2"
 				UsePrecompiledHeader="0"
 				WarningLevel="0"
-				Detect64BitPortabilityProblems="true"
 				DebugInformationFormat="3"
 			/>
 			<Tool