diff --git a/overview.md b/overview.md
index 7d82fc1..cc90511 100644
--- a/overview.md
+++ b/overview.md
@@ -62,6 +62,14 @@ available as soon as they are created.
     - [ ] JSON support for structures
     - [ ] What's the deal with pointers?
         - [ ] pointers make values mutable across functions
+- [ ] Interfaces
+    - [ ] What is an interface?
+    - [ ] Defining them
+    - [ ] Using them
+    - [ ] Errors
+        - [ ] Handling errors
+        - [ ] Package errors
+        - [ ] Making your own error types
 - [ ] HTTP operations
     - [ ] fetching data from canhazip.com
     - [ ] validating response