diff --git a/install-scripts/install-safe-chain.ps1 b/install-scripts/install-safe-chain.ps1
index 9c0dcf7..23caa5c 100644
--- a/install-scripts/install-safe-chain.ps1
+++ b/install-scripts/install-safe-chain.ps1
@@ -3,7 +3,8 @@
 # Usage with "iex (iwr {url} -UseBasicParsing)" --> See README.md
 
 param(
-    [switch]$ci
+    [switch]$ci,
+    [switch]$includepython
 )
 
 $Version = $env:SAFE_CHAIN_VERSION  # Will be fetched from latest release if not set
@@ -119,6 +120,9 @@ function Install-SafeChain {
     if ($ci) {
         $installMsg += " in ci"
     }
+    if ($includepython) {
+        Write-Warn "-includepython is deprecated and ignored. Python ecosystem is now included by default."
+    }
 
     Write-Info $installMsg
 
diff --git a/install-scripts/install-safe-chain.sh b/install-scripts/install-safe-chain.sh
index 37d1710..8e19da7 100755
--- a/install-scripts/install-safe-chain.sh
+++ b/install-scripts/install-safe-chain.sh
@@ -134,6 +134,9 @@ parse_arguments() {
             --ci)
                 USE_CI_SETUP=true
                 ;;
+            --include-python)
+                warn "--include-python is deprecated and ignored. Python ecosystem is now included by default."
+                ;;
             *)
                 error "Unknown argument: $arg"
                 ;;
diff --git a/packages/safe-chain/src/config/cliArguments.js b/packages/safe-chain/src/config/cliArguments.js
index 4dd9336..25013fb 100644
--- a/packages/safe-chain/src/config/cliArguments.js
+++ b/packages/safe-chain/src/config/cliArguments.js
@@ -1,3 +1,5 @@
+import { ui } from "../environment/userInteraction.js";
+
 /**
  * @type {{loggingLevel: string | undefined, skipMinimumPackageAge: boolean | undefined, minimumPackageAgeHours: string | undefined}}
  */
@@ -33,7 +35,7 @@ export function initializeCliArguments(args) {
   setLoggingLevel(safeChainArgs);
   setSkipMinimumPackageAge(safeChainArgs);
   setMinimumPackageAgeHours(safeChainArgs);
-
+  checkDeprecatedPythonFlag(args);
   return remainingArgs;
 }
 
@@ -120,3 +122,17 @@ function hasFlagArg(args, flagName) {
   }
   return false;
 }
+
+/**
+ * Emits a deprecation warning for legacy --include-python flag
+ *
+ * @param {string[]} args
+ * @returns {void}
+ */
+export function checkDeprecatedPythonFlag(args) {
+  if (hasFlagArg(args, "--include-python")) {
+    ui.writeWarning(
+      "--include-python is deprecated and ignored. Python tooling is included by default."
+    );
+  }
+}
diff --git a/packages/safe-chain/src/config/cliArguments.spec.js b/packages/safe-chain/src/config/cliArguments.spec.js
index bbd5121..8b505be 100644
--- a/packages/safe-chain/src/config/cliArguments.spec.js
+++ b/packages/safe-chain/src/config/cliArguments.spec.js
@@ -6,6 +6,7 @@ import {
   getSkipMinimumPackageAge,
   getMinimumPackageAgeHours,
 } from "./cliArguments.js";
+import { ui } from "../environment/userInteraction.js";
 
 describe("initializeCliArguments", () => {
   it("should return all args when no safe-chain args are present", () => {
@@ -271,4 +272,40 @@ describe("initializeCliArguments", () => {
 
     assert.strictEqual(getMinimumPackageAgeHours(), "-24");
   });
+
+  it("should warn on deprecated --include-python for setup", () => {
+    const warnings = [];
+    const originalWriteWarning = ui.writeWarning;
+    ui.writeWarning = (msg, ..._rest) => {
+      warnings.push(String(msg));
+    };
+    try {
+      const argv = ["node", "safe-chain", "setup", "--include-python"];
+      initializeCliArguments(argv);
+      assert.ok(
+        warnings.some((m) => m.includes("--include-python is deprecated")),
+        "Expected a deprecation warning for --include-python in setup"
+      );
+    } finally {
+      ui.writeWarning = originalWriteWarning;
+    }
+  });
+
+  it("should warn on deprecated --include-python for setup-ci", () => {
+    const warnings = [];
+    const originalWriteWarning = ui.writeWarning;
+    ui.writeWarning = (msg, ..._rest) => {
+      warnings.push(String(msg));
+    };
+    try {
+      const argv = ["node", "safe-chain", "setup-ci", "--include-python"];
+      initializeCliArguments(argv);
+      assert.ok(
+        warnings.some((m) => m.includes("--include-python is deprecated")),
+        "Expected a deprecation warning for --include-python in setup-ci"
+      );
+    } finally {
+      ui.writeWarning = originalWriteWarning;
+    }
+  });
 });
diff --git a/test/e2e/include-python-deprecation.e2e.spec.js b/test/e2e/include-python-deprecation.e2e.spec.js
new file mode 100644
index 0000000..a7019b7
--- /dev/null
+++ b/test/e2e/include-python-deprecation.e2e.spec.js
@@ -0,0 +1,45 @@
+import { describe, it, before, beforeEach, afterEach } from "node:test";
+import { DockerTestContainer } from "./DockerTestContainer.js";
+import assert from "node:assert";
+
+describe("E2E: deprecated --include-python handling", () => {
+  let container;
+
+  before(async () => {
+    DockerTestContainer.buildImage();
+  });
+
+  beforeEach(async () => {
+    container = new DockerTestContainer();
+    await container.start();
+  });
+
+  afterEach(async () => {
+    if (container) {
+      await container.stop();
+      container = null;
+    }
+  });
+
+  for (let shell of ["bash", "zsh"]) {
+    it(`safe-chain setup warns and continues for ${shell}`, async () => {
+      const sh = await container.openShell(shell);
+      const result = await sh.runCommand("safe-chain setup --include-python");
+
+      assert.ok(
+        result.output.toLowerCase().includes("deprecated and ignored"),
+        `Expected warning about deprecated --include-python. Output was:\n${result.output}`
+      );
+    });
+
+    it(`safe-chain setup-ci warns and continues for ${shell}`, async () => {
+      const sh = await container.openShell(shell);
+      const result = await sh.runCommand("safe-chain setup-ci --include-python");
+
+      assert.ok(
+        result.output.toLowerCase().includes("deprecated and ignored"),
+        `Expected warning about deprecated --include-python. Output was:\n${result.output}`
+      );
+    });
+  }
+});