diff --git a/completion/available/pip.completion.bash b/completion/available/pip.completion.bash
index ad3abb7e..618909ad 100644
--- a/completion/available/pip.completion.bash
+++ b/completion/available/pip.completion.bash
@@ -1,11 +1,10 @@
-
-# pip bash completion start
-_pip_completion()
-{
-    COMPREPLY=( $( COMP_WORDS="${COMP_WORDS[*]}" \
-                   COMP_CWORD=$COMP_CWORD \
-                   PIP_AUTO_COMPLETE=1 $1 ) )
-}
-complete -o default -F _pip_completion pip
-# pip bash completion end
-
+# https://pip.pypa.io/en/stable/user_guide/#command-completion
+# Of course, you should first install the pip, say on Debian:
+# sudo apt-get install python-pip
+# sudo apt-get install python3-pip
+# If the pip package is installed within virtual environments, say, python managed by pyenv,
+# you should first initilization the corresponding environment.
+# So that the pip/pip3 is in system's path.
+if command -v pip >/dev/null; then
+  eval "$(pip completion --bash)"
+fi
diff --git a/completion/available/pip3.completion.bash b/completion/available/pip3.completion.bash
index 1800756b..599e96e5 100644
--- a/completion/available/pip3.completion.bash
+++ b/completion/available/pip3.completion.bash
@@ -1,11 +1,11 @@
-
-# pip bash completion start
-_pip_completion()
-{
-    COMPREPLY=( $( COMP_WORDS="${COMP_WORDS[*]}" \
-                   COMP_CWORD=$COMP_CWORD \
-                   PIP_AUTO_COMPLETE=1 $1 ) )
-}
-complete -o default -F _pip_completion pip3
-# pip bash completion end
+# https://pip.pypa.io/en/stable/user_guide/#command-completion
+# Of course, you should first install the pip, say on Debian:
+# sudo apt-get install python-pip
+# sudo apt-get install python3-pip
+# If the pip package is installed within virtual environments, say, python managed by pyenv,
+# you should first initilization the corresponding environment.
+# So that the pip/pip3 is in system's path.
+if command -v pip3 >/dev/null; then
+  eval "$(pip3 completion --bash)"
+fi