diff --git a/samples/Advanced.Localization/Resources/Program.ja-jp.resx b/samples/Advanced.Localization/Resources/Program.ja-JP.resx
similarity index 100%
rename from samples/Advanced.Localization/Resources/Program.ja-jp.resx
rename to samples/Advanced.Localization/Resources/Program.ja-JP.resx
diff --git a/samples/Advanced.Localization/Resources/Program.ko-kr.resx b/samples/Advanced.Localization/Resources/Program.ko-KR.resx
similarity index 100%
rename from samples/Advanced.Localization/Resources/Program.ko-kr.resx
rename to samples/Advanced.Localization/Resources/Program.ko-KR.resx
diff --git a/src/Cocona.Core/Cocona.Core.csproj b/src/Cocona.Core/Cocona.Core.csproj
index 99c22ff..0bc4735 100644
--- a/src/Cocona.Core/Cocona.Core.csproj
+++ b/src/Cocona.Core/Cocona.Core.csproj
@@ -58,10 +58,10 @@
       <Generator>ResXFileCodeGenerator</Generator>
       <LastGenOutput>String.Designer.cs</LastGenOutput>
     </EmbeddedResource>
-    <EmbeddedResource Update="Resources\Strings.ja-jp.resx">
+    <EmbeddedResource Update="Resources\Strings.ja-JP.resx">
       <DependentUpon>Strings.resx</DependentUpon>
     </EmbeddedResource>
-    <EmbeddedResource Update="Resources\Strings.ko-kr.resx">
+    <EmbeddedResource Update="Resources\Strings.ko-KR.resx">
       <DependentUpon>Strings.resx</DependentUpon>
     </EmbeddedResource>
     <EmbeddedResource Update="Resources\Strings.resx">
diff --git a/src/Cocona.Core/Resources/Strings.ja-jp.resx b/src/Cocona.Core/Resources/Strings.ja-JP.resx
similarity index 100%
rename from src/Cocona.Core/Resources/Strings.ja-jp.resx
rename to src/Cocona.Core/Resources/Strings.ja-JP.resx
diff --git a/src/Cocona.Core/Resources/Strings.ko-kr.resx b/src/Cocona.Core/Resources/Strings.ko-KR.resx
similarity index 100%
rename from src/Cocona.Core/Resources/Strings.ko-kr.resx
rename to src/Cocona.Core/Resources/Strings.ko-KR.resx
diff --git a/src/Cocona.Lite/Cocona.Lite.csproj b/src/Cocona.Lite/Cocona.Lite.csproj
index 75ca7d1..2187f45 100644
--- a/src/Cocona.Lite/Cocona.Lite.csproj
+++ b/src/Cocona.Lite/Cocona.Lite.csproj
@@ -40,10 +40,10 @@
   </ItemGroup>
 
   <ItemGroup>
-    <EmbeddedResource Update="Lite\Resources\Strings.ja-jp.resx">
+    <EmbeddedResource Update="Lite\Resources\Strings.ja-JP.resx">
       <DependentUpon>Strings.resx</DependentUpon>
     </EmbeddedResource>
-    <EmbeddedResource Update="Lite\Resources\Strings.ko-kr.resx">
+    <EmbeddedResource Update="Lite\Resources\Strings.ko-KR.resx">
       <DependentUpon>Strings.resx</DependentUpon>
     </EmbeddedResource>
     <EmbeddedResource Update="Lite\Resources\Strings.resx">
diff --git a/src/Cocona.Lite/Lite/Resources/Strings.ja-jp.resx b/src/Cocona.Lite/Lite/Resources/Strings.ja-JP.resx
similarity index 100%
rename from src/Cocona.Lite/Lite/Resources/Strings.ja-jp.resx
rename to src/Cocona.Lite/Lite/Resources/Strings.ja-JP.resx
diff --git a/src/Cocona.Lite/Lite/Resources/Strings.ko-kr.resx b/src/Cocona.Lite/Lite/Resources/Strings.ko-KR.resx
similarity index 100%
rename from src/Cocona.Lite/Lite/Resources/Strings.ko-kr.resx
rename to src/Cocona.Lite/Lite/Resources/Strings.ko-KR.resx
diff --git a/src/Cocona/Cocona.csproj b/src/Cocona/Cocona.csproj
index 6fe7491..bbd4b2c 100644
--- a/src/Cocona/Cocona.csproj
+++ b/src/Cocona/Cocona.csproj
@@ -41,10 +41,10 @@
   </ItemGroup>
 
   <ItemGroup>
-    <EmbeddedResource Update="Resources\Strings.ja-jp.resx">
+    <EmbeddedResource Update="Resources\Strings.ja-JP.resx">
       <DependentUpon>Strings.resx</DependentUpon>
     </EmbeddedResource>
-    <EmbeddedResource Update="Resources\Strings.ko-kr.resx">
+    <EmbeddedResource Update="Resources\Strings.ko-KR.resx">
       <DependentUpon>Strings.resx</DependentUpon>
     </EmbeddedResource>
     <EmbeddedResource Update="Resources\Strings.resx">
diff --git a/src/Cocona/Resources/Strings.ja-jp.resx b/src/Cocona/Resources/Strings.ja-JP.resx
similarity index 100%
rename from src/Cocona/Resources/Strings.ja-jp.resx
rename to src/Cocona/Resources/Strings.ja-JP.resx
diff --git a/src/Cocona/Resources/Strings.ko-kr.resx b/src/Cocona/Resources/Strings.ko-KR.resx
similarity index 100%
rename from src/Cocona/Resources/Strings.ko-kr.resx
rename to src/Cocona/Resources/Strings.ko-KR.resx