We don't have any mechanism to Delay signing for the assemblies for which we don't have sourced code. We have to emulate what the compiler does for us. Normally this happens when we use third party components that may not be delay signed. Generate the IL from the .NET assembly using ILDASM command. ildasm assemblyname .dll /out:assemblyname .il Rename the original assembly Generate the new assembly using the correct public key. ilasm assemblyname .il /dll /key=sample.snk Creating Interop Wrappers: In the Visual Studio .NET command prompt D:\> tlbimp COMComponent.dll /keyfile:sample.snk /out:Interop.COMComponent.dll The above line converts the unmanaged assembly to the managed assembly with the delay signing. For more information: http://msdn.microsoft.com