diff --git a/eng/referenceAssemblies.props b/eng/referenceAssemblies.props
index 35131d5fdf6064..a5e0e553f12f7a 100644
--- a/eng/referenceAssemblies.props
+++ b/eng/referenceAssemblies.props
@@ -1,7 +1,12 @@
 <Project>
-  <PropertyGroup>
-    <AdditionalBuildTargetFrameworks Condition="'$(BuildAllProjects)' == 'true'">$(AdditionalBuildTargetFrameworks);netstandard2.0;netstandard2.1</AdditionalBuildTargetFrameworks>    
+  <PropertyGroup Condition="'$(BuildAllProjects)' == 'true' and
+                            !$(BuildTargetFramework.StartsWith('netstandard'))">
+    <AdditionalBuildTargetFrameworks Condition="!$(BuildTargetFramework.StartsWith('net45'))">$(AdditionalBuildTargetFrameworks);netstandard2.0</AdditionalBuildTargetFrameworks>
+    <AdditionalBuildTargetFrameworks Condition="!$(BuildTargetFramework.StartsWith('netcoreapp2.0')) and
+                                                !$(BuildTargetFramework.StartsWith('net4'))">$(AdditionalBuildTargetFrameworks);netstandard2.1</AdditionalBuildTargetFrameworks>
+  </PropertyGroup>
 
+  <PropertyGroup>
     <!-- disable warnings about unused fields -->
     <NoWarn>$(NoWarn);CS0169;CS0649;CS8618</NoWarn>