diff --git a/eng/SourceBuild.props b/eng/SourceBuild.props
index 82b297b51f67..59feaabd07b4 100644
--- a/eng/SourceBuild.props
+++ b/eng/SourceBuild.props
@@ -40,6 +40,11 @@
       <_AdditionalRepoTaskBuildArgs Condition="'$(DotNetRuntimeSourceFeedKey)' != ''" >$(_AdditionalRepoTaskBuildArgs) --runtimesourcefeedkey $(DotNetRuntimeSourceFeedKey)</_AdditionalRepoTaskBuildArgs>
     </PropertyGroup>
 
+    <ItemGroup>
+      <!-- We need to flow FullAssemblySigningSupported even when building repo tasks because they use full signing -->
+      <InnerBuildEnv Condition="'$(FullAssemblySigningSupported)' != ''" Include="FullAssemblySigningSupported=$(FullAssemblySigningSupported)" />
+    </ItemGroup>
+
     <!-- Call the build.sh script to build the repo tasks. Set IgnoreStandardErrorWarningFormat
          to true. This avoids fatal errors, because in internal builds there are usually a few failed installation
          attempts as the install script walks through potential locations for a runtime.