diff --git a/.editorconfig b/.editorconfig
index 5c3c8c1395a..24cb45298a2 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -437,9 +437,6 @@ dotnet_diagnostic.IDE0330.severity = suggestion
 # Use implicitly typed lambda
 dotnet_diagnostic.IDE0350.severity = none
 
-#Nullable suppression is unnecessary (not when multi-targeting to net472): https://github.com/dotnet/msbuild/issues/12726
-dotnet_diagnostic.IDE0370.severity = none
-
 # Value types are incompatible with null values. https://xunit.net/xunit.analyzers/rules/xUnit1012
 dotnet_diagnostic.xUnit1012.severity = warning
 
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index cb83bc9c166..603ef6b403a 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -78,6 +78,14 @@
     <RuntimeOutputPlatformTarget>AnyCPU</RuntimeOutputPlatformTarget>
   </PropertyGroup>
 
+  <!-- Many BCL APIs aren't nullable-annotated on .NET Framework, forcing null-forgiving ('!') suppressions
+       that are unneeded (and flagged by IDE0370) on the other TFMs of multi-targeted projects.
+       Disable nullable analysis for the net4x leg of such projects so those suppressions become unnecessary
+       everywhere. https://github.com/dotnet/msbuild/issues/12726 -->
+  <PropertyGroup Condition="'$(TargetFramework)' != '' and $(TargetFramework.StartsWith('net4')) and $(TargetFrameworks.Contains(';'))">
+    <Nullable>disable</Nullable>
+  </PropertyGroup>
+
   <PropertyGroup>
     <TargetsForTfmSpecificBuildOutput>$(TargetsForTfmSpecificContentInPackage);ShipRefAssembliesToNuGetPackage</TargetsForTfmSpecificBuildOutput>
   </PropertyGroup>