diff --git a/Visual Studio Projects/MicroVAX1.vcproj b/Visual Studio Projects/MicroVAX1.vcproj
index b0f1ad52..7ab9c39e 100644
--- a/Visual Studio Projects/MicroVAX1.vcproj	
+++ b/Visual Studio Projects/MicroVAX1.vcproj	
@@ -249,6 +249,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -258,6 +259,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/MicroVAX2.vcproj b/Visual Studio Projects/MicroVAX2.vcproj
index 87e24f6c..66b8cb67 100644
--- a/Visual Studio Projects/MicroVAX2.vcproj	
+++ b/Visual Studio Projects/MicroVAX2.vcproj	
@@ -249,6 +249,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -258,6 +259,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/PDP10.vcproj b/Visual Studio Projects/PDP10.vcproj
index 7665a58d..ec50b14c 100644
--- a/Visual Studio Projects/PDP10.vcproj	
+++ b/Visual Studio Projects/PDP10.vcproj	
@@ -275,6 +275,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -284,6 +285,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/PDP11.vcproj b/Visual Studio Projects/PDP11.vcproj
index 15308d58..3faee1ea 100644
--- a/Visual Studio Projects/PDP11.vcproj	
+++ b/Visual Studio Projects/PDP11.vcproj	
@@ -371,6 +371,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -380,6 +381,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/VAX.vcproj b/Visual Studio Projects/VAX.vcproj
index 6b43e13c..e94df43a 100644
--- a/Visual Studio Projects/VAX.vcproj	
+++ b/Visual Studio Projects/VAX.vcproj	
@@ -253,6 +253,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -262,6 +263,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/VAX730.vcproj b/Visual Studio Projects/VAX730.vcproj
index a19a0ecd..31367672 100644
--- a/Visual Studio Projects/VAX730.vcproj	
+++ b/Visual Studio Projects/VAX730.vcproj	
@@ -266,6 +266,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -275,6 +276,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/VAX750.vcproj b/Visual Studio Projects/VAX750.vcproj
index 2425dfbf..47f90fad 100644
--- a/Visual Studio Projects/VAX750.vcproj	
+++ b/Visual Studio Projects/VAX750.vcproj	
@@ -274,6 +274,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -283,6 +284,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/VAX780.vcproj b/Visual Studio Projects/VAX780.vcproj
index 556ee4ea..9c9b5656 100644
--- a/Visual Studio Projects/VAX780.vcproj	
+++ b/Visual Studio Projects/VAX780.vcproj	
@@ -279,6 +279,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -288,6 +289,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/VAX8600.vcproj b/Visual Studio Projects/VAX8600.vcproj
index 75edf389..5e65c70a 100644
--- a/Visual Studio Projects/VAX8600.vcproj	
+++ b/Visual Studio Projects/VAX8600.vcproj	
@@ -279,6 +279,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -288,6 +289,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>
diff --git a/Visual Studio Projects/rtVAX1000.vcproj b/Visual Studio Projects/rtVAX1000.vcproj
index c98e289c..d9918b0f 100644
--- a/Visual Studio Projects/rtVAX1000.vcproj	
+++ b/Visual Studio Projects/rtVAX1000.vcproj	
@@ -249,6 +249,7 @@
 					<Tool
 						Name="VCCLCompilerTool"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 				<FileConfiguration
@@ -258,6 +259,7 @@
 						Name="VCCLCompilerTool"
 						WholeProgramOptimization="false"
 						PreprocessorDefinitions="HAVE_PTW32_CONFIG_H;PTW32_BUILD_INLINED;PTW32_STATIC_LIB;__CLEANUP_C;$(NOINHERIT)"
+						CompileAs="1"
 					/>
 				</FileConfiguration>
 			</File>