diff --git a/src/zip.hpp b/src/zip.hpp
index b12acd4..ad036ec 100644
--- a/src/zip.hpp
+++ b/src/zip.hpp
@@ -26,8 +26,10 @@
 namespace epubgrep::zip
 {
 
+//! List the contents of a zip file.
 std::vector<std::string> list(const fs::path &filepath);
 
+// It's std::runtime_error, but with another name.
 class exception : public std::runtime_error
 {
 public: