diff --git a/INSTALL b/INSTALL
index 86f9e0080c..efc60bf63d 100644
--- a/INSTALL
+++ b/INSTALL
@@ -214,6 +214,33 @@ like 'apt-get build-dep emacs' (on older systems, replace 'emacs' with
 eg 'emacs25').  On Red Hat-based systems, the corresponding command is
 'dnf builddep emacs' (on older systems, use 'yum-builddep' instead).

+* GNU/Linux source and debug packages
+
+Many GNU/Linux systems provide separate packages containing the
+sources and debug symbols of Emacs.  They are useful if you want to
+check the source code of Emacs primitive functions or debug Emacs on
+the C level.
+
+The names of the packages that you need varies according to the
+GNU/Linux distribution that you use.  On Debian-based systems, you can
+install a source package of Emacs with a command like 'apt-get source
+emacs' (on older systems, replace 'emacs' with eg 'emacs25').  The
+target directory for unpacking the source tree is the current
+directory.  On Red Hat-based systems, the corresponding command is
+'dnf debuginfo-install emacs', with target directory /usr/src/debug.
+
+Once you have installed the source package, for example at
+/path/to/emacs-26.1, add the following line to your startup file:
+
+     (setq source-directory "/path/to/emacs-26.1")
+
+Emacs debugging symbols are distributed by a debug package.  It does
+not exists for every released Emacs package, this depends on the
+distribution.  On Debian-based systems, you can install a debug
+package of Emacs with a command like 'apt-get install emacs-dbg' (on
+older systems, replace 'emacs' with eg 'emacs25').  On Red Hat-based
+systems, the corresponding command is 'dnf debuginfo-install emacs'.
+

 DETAILED BUILDING AND INSTALLATION: