diff --git a/src/r-apt/README.md b/src/r-apt/README.md
index fcf24df..f00ce03 100644
--- a/src/r-apt/README.md
+++ b/src/r-apt/README.md
@@ -89,6 +89,8 @@ For more information, please check [the Rocker Project website](https://rocker-p
 This feature has some options to install Python packages such as `jupyterlab`.
 When installing Python packages, if `python3 -m pip` is not available, it will install `python3-pip` via apt.
 
+This feature set `PIP_BREAK_SYSTEM_PACKAGES=1` when installing Python packages.
+
 ## References
 
 - [Rocker Project](https://rocker-project.org)
diff --git a/src/r-rig/README.md b/src/r-rig/README.md
index a98cdd4..2128d8b 100644
--- a/src/r-rig/README.md
+++ b/src/r-rig/README.md
@@ -101,6 +101,8 @@ $ R -q -e 'pak::pak("curl")'
 This feature has some options to install Python packages such as `jupyterlab`.
 When installing Python packages, if `python3 -m pip` is not available, it will install `python3-pip` via apt.
 
+This feature set `PIP_BREAK_SYSTEM_PACKAGES=1` when installing Python packages.
+
 ## References
 
 - [rig](https://github.com/r-lib/rig)