From 972a47a5eb3da2a782e3ce8b0470cab7ba82ab8f Mon Sep 17 00:00:00 2001
From: Matthew Foran <46829130+mjforan@users.noreply.github.com>
Date: Mon, 21 Aug 2023 08:47:46 -0400
Subject: [PATCH] Improve eval documentation in migration guide (#3832)

(cherry picked from commit 28fa628cda610ffd190f682905628a399635f625)
---
 source/How-To-Guides/Launch-files-migration-guide.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/How-To-Guides/Launch-files-migration-guide.rst b/source/How-To-Guides/Launch-files-migration-guide.rst
index 3d7976a65e0..23f608003b5 100644
--- a/source/How-To-Guides/Launch-files-migration-guide.rst
+++ b/source/How-To-Guides/Launch-files-migration-guide.rst
@@ -400,7 +400,7 @@ There are, however, some changes w.r.t. ROS 1:
 * There is a new ``find-exec`` substitution.
 * ``arg`` has been replaced with ``var``.
   It looks at configurations defined either with ``arg`` or ``let`` tag.
-* ``eval`` and ``dirname`` substitutions require escape characters for string values, e.g. ``if="$(eval 'variable == \'val1\'')"``.
+* ``eval`` and ``dirname`` substitutions require escape characters for string values, e.g. ``if="$(eval '\'$(var variable)\' == \'val1\'')"``.
 * ``anon`` substitution is not supported.
 
 Type inference rules