Verb tense

Person A is waiting for a call from Person X and is asking person B about that. The conversation:
A: Hey B, did X call?

B: No, he hasn't called yet.

A: If he called, please make me aware of that.

B: Sure. I will tell you.

Now the question is, is the underlined sentence above correct? There, we have used a past tense structure (if he called) for a future even that may or may not happen.