diff --git a/HISTORY.rst b/HISTORY.rst
index a2c8f297..6c313133 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -35,6 +35,7 @@ PlatformIO Core 6
 * Allowed to ``Import("projenv")`` in a library extra script (`issue #4305 <https://github.com/platformio/platformio-core/issues/4305>`_)
 * Improved a serial port finder for `Black Magic Probe <https://docs.platformio.org/en/latest/plus/debug-tools/blackmagic.html>`__ (`issue #4023 <https://github.com/platformio/platformio-core/issues/4023>`_)
 * Improved a serial port finder for a board with predefined HWIDs
+* Warn about incompatible Bash version for the `Shell Completion <https://docs.platformio.org/en/latest/core/userguide/system/completion/index.html>`__ (`issue #4326 <https://github.com/platformio/platformio-core/issues/4326>`_)
 * Fixed an issue when the `build_unflags <https://docs.platformio.org/en/latest/projectconf/section_env_build.html#build-unflags>`__ operation ignores a flag value (`issue #4309 <https://github.com/platformio/platformio-core/issues/4309>`_)
 * Fixed an issue when the `build_unflags <https://docs.platformio.org/en/latest/projectconf/section_env_build.html#build-unflags>`__ option was not applied to the ``ASPPFLAGS`` scope
 * Fixed an issue on Windows OS when flags were wrapped to the temporary file while generating the `Compilation database "compile_commands.json" <https://docs.platformio.org/en/latest/integration/compile_commands.html>`__
diff --git a/platformio/system/completion.py b/platformio/system/completion.py
index 3ea80b99..3192021c 100644
--- a/platformio/system/completion.py
+++ b/platformio/system/completion.py
@@ -13,6 +13,8 @@
 # limitations under the License.
 
 import os
+import re
+import subprocess
 from enum import Enum
 
 import click
@@ -26,6 +28,14 @@ class ShellType(Enum):
     BASH = "bash"
 
 
+def get_bash_version():
+    result = subprocess.run(["bash", "--version"], capture_output=True, check=True)
+    match = re.search(r"version\s+(\d+)\.(\d+)", result.stdout.decode())
+    if match:
+        return (int(match.group(1)), int(match.group(2)))
+    return (0, 0)
+
+
 def get_completion_install_path(shell):
     home_dir = os.path.expanduser("~")
     prog_name = click.get_current_context().find_root().info_name
@@ -59,6 +69,8 @@ def is_completion_code_installed(shell, path):
 
 
 def install_completion_code(shell, path):
+    if shell == ShellType.BASH and get_bash_version() < (4, 4):
+        raise click.ClickException("The minimal supported Bash version is 4.4")
     if is_completion_code_installed(shell, path):
         return None
     append = shell != ShellType.FISH