diff --git a/doc/lispref/compile.texi b/doc/lispref/compile.texi
index 441ee9afb26..201d9fc2fa5 100644
--- a/doc/lispref/compile.texi
+++ b/doc/lispref/compile.texi
@@ -88,6 +88,7 @@ the @code{byte-compile} function.  You can compile a whole file with
 @code{byte-compile-file}, or several files with
 @code{byte-recompile-directory} or @code{batch-byte-compile}.
 
+@vindex byte-compile-debug
   Sometimes, the byte compiler produces warning and/or error messages
 (@pxref{Compiler Errors}, for details).  These messages are normally
 recorded in a buffer called @file{*Compile-Log*}, which uses