Keras Illegal Instruction 4

I have been trying to get Keras working on my laptop running El Capitan but when I attempt to import it I get the following message

Using TensorFlow backend.
Illegal instruction: 4

I've looked for solutions, and have tried updating theano, installing mxnet-mkl, and running an older version of numpy (1.13) to avoid a FutureWarning error. None of these has seemed to fix the issue, though. I feel like I must be missing something somewhere.

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