diff --git a/install-scripts/install-safe-chain.ps1 b/install-scripts/install-safe-chain.ps1
index af0e43d..23caa5c 100644
--- a/install-scripts/install-safe-chain.ps1
+++ b/install-scripts/install-safe-chain.ps1
@@ -4,7 +4,6 @@
 
 param(
     [switch]$ci,
-    # Backwards compatibility: deprecated; warn and ignore if supplied
     [switch]$includepython
 )
 
diff --git a/packages/safe-chain/src/config/cliArguments.js b/packages/safe-chain/src/config/cliArguments.js
index 71ab390..25013fb 100644
--- a/packages/safe-chain/src/config/cliArguments.js
+++ b/packages/safe-chain/src/config/cliArguments.js
@@ -130,8 +130,7 @@ function hasFlagArg(args, flagName) {
  * @returns {void}
  */
 export function checkDeprecatedPythonFlag(args) {
-  if (!Array.isArray(args)) return;
-  if (args.includes("--include-python")) {
+  if (hasFlagArg(args, "--include-python")) {
     ui.writeWarning(
       "--include-python is deprecated and ignored. Python tooling is included by default."
     );