diff --git a/Common/Common.csproj b/Common/Common.csproj
index cc78428c2..6d7c93884 100644
--- a/Common/Common.csproj
+++ b/Common/Common.csproj
@@ -17,7 +17,7 @@
     <DebugType>full</DebugType>
     <Optimize>false</Optimize>
     <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>TRACE;DEBUG</DefineConstants>
+    <DefineConstants>TRACE;DEBUG;LANG_PL</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
@@ -25,7 +25,7 @@
     <DebugType>pdbonly</DebugType>
     <Optimize>true</Optimize>
     <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
+    <DefineConstants>TRACE;LANG_PL</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
diff --git a/Results/Results.csproj b/Results/Results.csproj
index 3baa75d44..64e5d76aa 100644
--- a/Results/Results.csproj
+++ b/Results/Results.csproj
@@ -19,7 +19,7 @@
     <DebugType>full</DebugType>
     <Optimize>false</Optimize>
     <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>TRACE;DEBUG</DefineConstants>
+    <DefineConstants>TRACE;DEBUG;LANG_PL</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -29,7 +29,7 @@
     <DebugType>pdbonly</DebugType>
     <Optimize>true</Optimize>
     <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
+    <DefineConstants>TRACE;LANG_PL</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <Prefer32Bit>false</Prefer32Bit>