You can free explicitly loaded DLLs with a dllfree() or dlclose() request. This request is optional because the DLLs are automatically deleted by the runtime library when the enclave is terminated.

Implicitly loaded DLLs cannot be deleted from the DLL application code. They are deleted by the runtime library at enclave termination. Therefore, if a DLL has been both explicitly and implicitly loaded, the DLL can only be deleted by the runtime when the enclave is terminated.