diff --git a/plugins/perl/perl.vcxproj b/plugins/perl/perl.vcxproj
index bd4a89b1..8b5069c0 100644
--- a/plugins/perl/perl.vcxproj
+++ b/plugins/perl/perl.vcxproj
@@ -29,7 +29,7 @@
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;_USRDLL;PERL520_EXPORTS;$(OwnFlags);%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;_USRDLL;PERL520_EXPORTS;HAS_BOOL;$(OwnFlags);%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(IntDir);..\..\src\common;$(HexChatLib);$(PerlPath)\lib\CORE;$(Glib);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ClCompile>
     <Link>
@@ -49,7 +49,7 @@ move hexchat.pm.h "$(IntDir)"</Command>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
     <ClCompile>
-      <PreprocessorDefinitions>WIN32;_WIN64;_AMD64_;NDEBUG;_WINDOWS;_USRDLL;PERL520_EXPORTS;$(OwnFlags);%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;_WIN64;_AMD64_;NDEBUG;_WINDOWS;_USRDLL;PERL520_EXPORTS;HAS_BOOL;$(OwnFlags);%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(IntDir);..\..\src\common;$(HexChatLib);$(PerlPath)\lib\CORE;$(Glib);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ClCompile>
     <Link>