Said the Wrong Word

So, my husband is smart in many ways, however, he doesn't always say certain words the right way. For example: Alzheimer's is Alz-Timer's to him. I tried bringing it up indirectly by saying, "So many people say Alzheimer's wrong. They say old-timer's or Alz-Timer's, when it's actually Alzheimer's." He didn't get the hint and just referred to it as "Alz-timer's" again. Would you ladies correct your husband if he did this? I feel embarrassed for him, especially if we are speaking with friends and it happens. Or should I just let it go cuz it's really not a big deal?