diff --git a/Documentation/index.rst b/Documentation/index.rst
index 75b6c155..e5dfc053 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst
@@ -330,9 +330,11 @@ in :file:`config.yaml.template`.
 
 .. describe:: Distro
 
-   Defines Linux distribution to be used to build Gramine in. Currently tested
-   distros are Ubuntu 18.04, Ubuntu 20.04, Ubuntu 21.04, Debian 10, Debian 11
-   and CentOS 8. Default value is ``ubuntu:18.04``.
+   Defines Linux distribution to be used to build Gramine in. This distro should
+   match the distro underlying the application's Docker image; otherwise the
+   results may be unpredictable. Currently supported distros are Ubuntu 18.04,
+   Ubuntu 20.04, Ubuntu 21.04, Debian 10, Debian 11 and CentOS 8. Default value
+   is ``ubuntu:18.04``.
 
 .. describe:: Registry
 
diff --git a/config.yaml.template b/config.yaml.template
index 292fe33c..80629ca7 100644
--- a/config.yaml.template
+++ b/config.yaml.template
@@ -1,4 +1,8 @@
-# Specify the OS distro. Currently tested distros are
+# Specify the OS distro that is used to build Gramine, i.e., the distro from where the Gramine build
+# gets all tools and dependencies from. This distro should match the distro underlying the
+# application's Docker image; otherwise the results may be unpredictable.
+#
+# Currently supported distros are:
 # - ubuntu:18.04, ubuntu:20.04, ubuntu:21.04
 # - debian:10, debian:11
 # - centos:8