diff --git a/src/Microsoft.Xaml.Behaviors.Signing.targets b/src/Microsoft.Xaml.Behaviors.Signing.targets
index 89acfd7..ea2e6b3 100644
--- a/src/Microsoft.Xaml.Behaviors.Signing.targets
+++ b/src/Microsoft.Xaml.Behaviors.Signing.targets
@@ -15,7 +15,7 @@
       <Authenticode>Microsoft400</Authenticode>
       <StrongName>StrongName</StrongName>
     </FilesToSign>
-    <FilesToSign Include="$(OutputPath)Design\$(AssemblyName).dll">
+    <FilesToSign Include="$(OutputPath)Design\*.dll">
       <Authenticode>Microsoft400</Authenticode>
       <StrongName>StrongName</StrongName>
     </FilesToSign>