How to Exclude Posts from Internal Link Search

I am having trouble, when creating links, with the “Or link to existing content” option. When I enter a search phrase in the field, only my posts come up as results, and not my pages. I have not had this problem on other sites I’m built. How can I fix this so when I type in “history” to the search field, my History page comes up as a result? Right now, the “History” page does not come up, but every post I’ve ever written with the word “history” in it does come up.

Thanks!
Nick