diff --git a/projects/openttd_vs80.vcproj.in b/projects/openttd_vs80.vcproj.in
--- a/projects/openttd_vs80.vcproj.in
+++ b/projects/openttd_vs80.vcproj.in
@@ -59,8 +59,8 @@
 				EnableIntrinsicFunctions="true"
 				FavorSizeOrSpeed="2"
 				OmitFramePointers="true"
-				AdditionalIncludeDirectories="..\objs\langs"
-				PreprocessorDefinitions="WIN32;NDEBUG;_CONSOLE;WIN32_EXCEPTION_TRACKER;WIN32_ENABLE_DIRECTMUSIC_SUPPORT;WITH_ZLIB;WITH_PNG;WITH_FREETYPE;WITH_ICU;ENABLE_NETWORK;WITH_PERSONAL_DIR;PERSONAL_DIR=\"OpenTTD\";WITH_ASSERT"
+				AdditionalIncludeDirectories="..\objs\langs;..\src\3rdparty\squirrel\include"
+				PreprocessorDefinitions="WIN32;NDEBUG;_CONSOLE;WIN32_EXCEPTION_TRACKER;WIN32_ENABLE_DIRECTMUSIC_SUPPORT;WITH_ZLIB;WITH_PNG;WITH_FREETYPE;WITH_ICU;ENABLE_NETWORK;WITH_PERSONAL_DIR;PERSONAL_DIR=\"OpenTTD\";NO_GARBAGE_COLLECTOR;WITH_ASSERT"
 				StringPooling="true"
 				ExceptionHandling="1"
 				RuntimeLibrary="0"
@@ -166,8 +166,8 @@
 				Name="VCCLCompilerTool"
 				AdditionalOptions="/MP"
 				Optimization="0"
-				AdditionalIncludeDirectories="..\objs\langs"
-				PreprocessorDefinitions="WIN32;_DEBUG;_CONSOLE;WIN32_ENABLE_DIRECTMUSIC_SUPPORT;WITH_ZLIB;WITH_PNG;WITH_FREETYPE;WITH_ICU;ENABLE_NETWORK;WITH_PERSONAL_DIR;PERSONAL_DIR=\"OpenTTD\""
+				AdditionalIncludeDirectories="..\objs\langs;..\src\3rdparty\squirrel\include"
+				PreprocessorDefinitions="WIN32;_DEBUG;_CONSOLE;WIN32_ENABLE_DIRECTMUSIC_SUPPORT;WITH_ZLIB;WITH_PNG;WITH_FREETYPE;WITH_ICU;ENABLE_NETWORK;WITH_PERSONAL_DIR;PERSONAL_DIR=\"OpenTTD\";NO_GARBAGE_COLLECTOR"
 				BasicRuntimeChecks="3"
 				RuntimeLibrary="1"
 				UsePrecompiledHeader="0"
@@ -268,8 +268,8 @@
 				EnableIntrinsicFunctions="true"
 				FavorSizeOrSpeed="2"
 				OmitFramePointers="true"
-				AdditionalIncludeDirectories="..\objs\langs"
-				PreprocessorDefinitions="WIN32;NDEBUG;_CONSOLE;WIN32_EXCEPTION_TRACKER;WIN32_ENABLE_DIRECTMUSIC_SUPPORT;WITH_ZLIB;WITH_PNG;WITH_FREETYPE;WITH_ICU;ENABLE_NETWORK;WITH_PERSONAL_DIR;PERSONAL_DIR=\"OpenTTD\";WITH_ASSERT"
+				AdditionalIncludeDirectories="..\objs\langs;..\src\3rdparty\squirrel\include"
+				PreprocessorDefinitions="WIN32;NDEBUG;_CONSOLE;WIN32_EXCEPTION_TRACKER;WIN32_ENABLE_DIRECTMUSIC_SUPPORT;WITH_ZLIB;WITH_PNG;WITH_FREETYPE;WITH_ICU;ENABLE_NETWORK;WITH_PERSONAL_DIR;PERSONAL_DIR=\"OpenTTD\";NO_GARBAGE_COLLECTOR;_SQ64;WITH_ASSERT"
 				StringPooling="true"
 				ExceptionHandling="1"
 				RuntimeLibrary="0"
@@ -376,8 +376,8 @@
 				Name="VCCLCompilerTool"
 				AdditionalOptions="/MP"
 				Optimization="0"
-				AdditionalIncludeDirectories="..\objs\langs"
-				PreprocessorDefinitions="WIN32;_DEBUG;_CONSOLE;WIN32_ENABLE_DIRECTMUSIC_SUPPORT;WITH_ZLIB;WITH_PNG;WITH_FREETYPE;WITH_ICU;ENABLE_NETWORK;WITH_PERSONAL_DIR;PERSONAL_DIR=\"OpenTTD\""
+				AdditionalIncludeDirectories="..\objs\langs;..\src\3rdparty\squirrel\include"
+				PreprocessorDefinitions="WIN32;_DEBUG;_CONSOLE;WIN32_ENABLE_DIRECTMUSIC_SUPPORT;WITH_ZLIB;WITH_PNG;WITH_FREETYPE;WITH_ICU;ENABLE_NETWORK;WITH_PERSONAL_DIR;PERSONAL_DIR=\"OpenTTD\";NO_GARBAGE_COLLECTOR;_SQ64"
 				BasicRuntimeChecks="3"
 				RuntimeLibrary="1"
 				UsePrecompiledHeader="0"