diff --git a/doc/api/mainpage.dox b/doc/api/mainpage.dox
index e7be4fa..471ed77 100644
--- a/doc/api/mainpage.dox
+++ b/doc/api/mainpage.dox
@@ -29,7 +29,7 @@ process them.
 The two libraries are independently and usually consumers of either `libei` or
 `libeis` should never need the other library.
 
-@section ei EI - the client implementation
+@section sec-ei EI - the client implementation
 
 The `libei` library is the component used by clients that want to emulate
 input events. It provides the required methods to connect to an EIS
@@ -38,7 +38,7 @@ input.
 
 The API documentation for EI is available at @ref libei.
 
-@section eis EIS - the server implementation
+@section sec-eis EIS - the server implementation
 
 The `libeis` library is the component used by processes that handle input
 events. It provides the required methods to set up seats and input devices,