diff --git a/.github/workflows/validate-nuget-publish.yml b/.github/workflows/validate-nuget-publish.yml
index f0fd6be1..48943086 100644
--- a/.github/workflows/validate-nuget-publish.yml
+++ b/.github/workflows/validate-nuget-publish.yml
@@ -9,4 +9,4 @@ on:
 jobs:
   validate-nuget-publish:
     name: Validate NuGet Publish
-    uses: Lombiq/GitHub-Actions/.github/workflows/validate-nuget-publish.yml@issue/OSOE-925
+    uses: Lombiq/GitHub-Actions/.github/workflows/validate-nuget-publish.yml@issue/OSOE-1199
diff --git a/Lombiq.HelpfulExtensions.sln b/Lombiq.HelpfulExtensions.sln
deleted file mode 100644
index f9569097..00000000
--- a/Lombiq.HelpfulExtensions.sln
+++ /dev/null
@@ -1,31 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.1.32319.34
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Lombiq.HelpfulExtensions", "Lombiq.HelpfulExtensions\Lombiq.HelpfulExtensions.csproj", "{207243C1-5934-4D94-AAF2-F46D4DB2F20F}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Lombiq.HelpfulExtensions.Tests.UI", "Lombiq.HelpfulExtensions.Tests.UI\Lombiq.HelpfulExtensions.Tests.UI.csproj", "{B1077AC7-10D3-451C-B467-DA0B4D7BD5A4}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Release|Any CPU = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{207243C1-5934-4D94-AAF2-F46D4DB2F20F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{207243C1-5934-4D94-AAF2-F46D4DB2F20F}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{207243C1-5934-4D94-AAF2-F46D4DB2F20F}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{207243C1-5934-4D94-AAF2-F46D4DB2F20F}.Release|Any CPU.Build.0 = Release|Any CPU
-		{B1077AC7-10D3-451C-B467-DA0B4D7BD5A4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{B1077AC7-10D3-451C-B467-DA0B4D7BD5A4}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{B1077AC7-10D3-451C-B467-DA0B4D7BD5A4}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{B1077AC7-10D3-451C-B467-DA0B4D7BD5A4}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-	GlobalSection(ExtensibilityGlobals) = postSolution
-		SolutionGuid = {5F8B26CF-89E9-487E-B4B0-643F1A109459}
-	EndGlobalSection
-EndGlobal
diff --git a/Lombiq.HelpfulExtensions.slnx b/Lombiq.HelpfulExtensions.slnx
new file mode 100644
index 00000000..65251805
--- /dev/null
+++ b/Lombiq.HelpfulExtensions.slnx
@@ -0,0 +1,4 @@
+<Solution>
+  <Project Path="Lombiq.HelpfulExtensions.Tests.UI/Lombiq.HelpfulExtensions.Tests.UI.csproj" />
+  <Project Path="Lombiq.HelpfulExtensions/Lombiq.HelpfulExtensions.csproj" />
+</Solution>