diff --git a/clean_files.txt b/clean_files.txt
index ddafc469..54cf3152 100644
--- a/clean_files.txt
+++ b/clean_files.txt
@@ -68,6 +68,9 @@ completion/available/github-cli.completion.bash
 completion/available/helm.completion.bash
 completion/available/knife.completion.bash
 completion/available/packer.completion.bash
+completion/available/pip.completion.bash
+completion/available/pip3.completion.bash
+completion/available/pipenv.completion.bash
 completion/available/pipx.completion.bash
 completion/available/rustup.completion.bash
 completion/available/vault.completion.bash
diff --git a/completion/available/pip.completion.bash b/completion/available/pip.completion.bash
index 618909ad..7ed8c17e 100644
--- a/completion/available/pip.completion.bash
+++ b/completion/available/pip.completion.bash
@@ -1,10 +1,11 @@
+# shellcheck shell=bash
+
 # https://pip.pypa.io/en/stable/user_guide/#command-completion
-# Of course, you should first install the pip, say on Debian:
+# Of course, you should first install pip, say on Debian:
 # sudo apt-get install python-pip
-# sudo apt-get install python3-pip
 # If the pip package is installed within virtual environments, say, python managed by pyenv,
-# you should first initilization the corresponding environment.
-# So that the pip/pip3 is in system's path.
-if command -v pip >/dev/null; then
-  eval "$(pip completion --bash)"
+# you should first initialize the corresponding environment.
+# So that pip is in the system's path.
+if _command_exists pip; then
+	eval "$(pip completion --bash)"
 fi
diff --git a/completion/available/pip3.completion.bash b/completion/available/pip3.completion.bash
index 1e2ffb42..c2b58564 100644
--- a/completion/available/pip3.completion.bash
+++ b/completion/available/pip3.completion.bash
@@ -1,10 +1,11 @@
+# shellcheck shell=bash
+
 # https://pip.pypa.io/en/stable/user_guide/#command-completion
-# Of course, you should first install the pip, say on Debian:
-# sudo apt-get install python-pip
+# Of course, you should first install pip, say on Debian:
 # sudo apt-get install python3-pip
 # If the pip package is installed within virtual environments, say, python managed by pyenv,
-# you should first initilization the corresponding environment.
-# So that the pip/pip3 is in system's path.
-if command -v pip3 >/dev/null; then
-  eval "$(pip3 completion --bash)"
+# you should first initialize the corresponding environment.
+# So that pip3 is in the system's path.
+if _command_exists pip3; then
+	eval "$(pip3 completion --bash)"
 fi
diff --git a/completion/available/pipenv.completion.bash b/completion/available/pipenv.completion.bash
index 339509f2..52451b8a 100644
--- a/completion/available/pipenv.completion.bash
+++ b/completion/available/pipenv.completion.bash
@@ -1 +1,4 @@
-[[ -x "$(which pipenv)" ]] && eval "$(pipenv --completion)"
+# shellcheck shell=bash
+if _command_exists pipenv; then
+	eval "$(pipenv --completion)"
+fi