diff --git a/Directory.Build.props b/Directory.Build.props
index 42d713f8e0d22d..9a7215424f7348 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -120,7 +120,7 @@
     <_parseDistroRid>$(__DistroRid)</_parseDistroRid>
     <_parseDistroRid Condition="'$(_parseDistroRid)' == '' and '$(MSBuildRuntimeType)' == 'core'">$([System.Runtime.InteropServices.RuntimeInformation]::RuntimeIdentifier)</_parseDistroRid>
     <_parseDistroRid Condition="'$(_parseDistroRid)' == '' and '$(MSBuildRuntimeType)' != 'core'">win-$([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture.ToString().ToLowerInvariant)</_parseDistroRid>
-    <_distroRidIndex>$(_parseDistroRid.LastIndexOfAny("-"))</_distroRidIndex>
+    <_distroRidIndex>$(_parseDistroRid.LastIndexOf('-'))</_distroRidIndex>
 
     <_runtimeOS>$(RuntimeOS)</_runtimeOS>
     <_runtimeOS Condition="'$(_runtimeOS)' == ''">$(_parseDistroRid.SubString(0, $(_distroRidIndex)))</_runtimeOS>
diff --git a/eng/SourceBuild.props b/eng/SourceBuild.props
index c9ac54d245a8bd..8db0cb0ee5c6cf 100644
--- a/eng/SourceBuild.props
+++ b/eng/SourceBuild.props
@@ -16,7 +16,7 @@
     <TargetRid Condition="'$(TargetRid)' == ''">$(__DistroRid)</TargetRid>
 
     <!-- Split e.g. 'fedora.33-x64' into 'fedora.33' and 'x64'. -->
-    <_targetRidPlatformIndex>$(TargetRid.LastIndexOfAny("-"))</_targetRidPlatformIndex>
+    <_targetRidPlatformIndex>$(TargetRid.LastIndexOf('-'))</_targetRidPlatformIndex>
     <TargetRidWithoutPlatform>$(TargetRid.Substring(0, $(_targetRidPlatformIndex)))</TargetRidWithoutPlatform>
     <TargetRidPlatform>$(TargetRid.Substring($(_targetRidPlatformIndex)).TrimStart('-'))</TargetRidPlatform>