Some tritium, a little lithium and a fancier casing.
Don't forget deuterium...and an order of magnitude more sophistication in detonation timing...plus the core fission bomb to generate enough heat to start the fusion reaction...and, just for color, try it in a fission-fusion-fission configuration by encasing it all in a U-238 shell so that the fusion reaction will saturate the U-238 with free neutrons, thus changing it to Plutonium which is then scattered across several miles.
Ah yes...there are fates worse than death. Most are my hobbies.