diff --git a/Visual Studio Projects/PDP11.vcproj b/Visual Studio Projects/PDP11.vcproj
index 40d852bd..15308d58 100644
--- a/Visual Studio Projects/PDP11.vcproj	
+++ b/Visual Studio Projects/PDP11.vcproj	
@@ -378,6 +378,7 @@
 					>
 					<Tool
 						Name="VCCLCompilerTool"
+						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
 					/>
 				</FileConfiguration>
diff --git a/Visual Studio Projects/VAX730.vcproj b/Visual Studio Projects/VAX730.vcproj
index 1ca445db..5889819c 100644
--- a/Visual Studio Projects/VAX730.vcproj	
+++ b/Visual Studio Projects/VAX730.vcproj	
@@ -265,6 +265,7 @@
 					>
 					<Tool
 						Name="VCCLCompilerTool"
+						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
 					/>
 				</FileConfiguration>
diff --git a/Visual Studio Projects/VAX750.vcproj b/Visual Studio Projects/VAX750.vcproj
index bc624a44..ec3ec778 100644
--- a/Visual Studio Projects/VAX750.vcproj	
+++ b/Visual Studio Projects/VAX750.vcproj	
@@ -273,6 +273,7 @@
 					>
 					<Tool
 						Name="VCCLCompilerTool"
+						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
 					/>
 				</FileConfiguration>