diff -r 4f5b32a2a60f -r e160bb392148 make/vs/testapp/testapp.vcxproj
--- a/make/vs/testapp/testapp.vcxproj	Sun Jan 28 09:35:44 2024 +0100
+++ b/make/vs/testapp/testapp.vcxproj	Sun Jan 28 10:06:54 2024 +0100
@@ -115,6 +115,7 @@
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;UI_WINUI;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>C:\Users\Olaf\Projekte\toolkit\ui;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <LanguageStandard_C>stdc17</LanguageStandard_C>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>