diff --git a/.github/ISSUE_TEMPLATE/api-change-proposal.md b/.github/ISSUE_TEMPLATE/api-change-proposal.md
index b2886d8..8e68eed 100644
--- a/.github/ISSUE_TEMPLATE/api-change-proposal.md
+++ b/.github/ISSUE_TEMPLATE/api-change-proposal.md
@@ -21,6 +21,8 @@ assignees: ""
 <!--
 If you have a sketch of a concrete solution, please include it here. You don't have to have all the details worked out, but it should be enough to convey the idea.
 
+For any functions or traits you do provide, please write out the *full type signature* (arguments, return type, trait bounds etc.) This is a critical portion of the API and it helps the team understand what exactly you are proposing.
+
 If you want to quickly check whether *any* some solution to the problem would be acceptable, you can delete this section.
 -->