diff --git a/Makefile b/Makefile
index 961ae90..34dc742 100644
--- a/Makefile
+++ b/Makefile
@@ -71,6 +71,8 @@ endif
 
 CPPFLAGS += $(DEFS) $(INCLUDES)
 
+BASHCOMPDIR ?= $(shell $(PKG_CONFIG) --variable=completionsdir bash-completion 2>/dev/null || echo /etc/bash_completion.d)
+
 ##############################################################################
 all: Makefile.depend whois mkpasswd pos
 
@@ -121,7 +123,7 @@ afl-run:
 	nice afl-fuzz -i ../afl_in -o ../afl_out -- ./whois
 
 ##############################################################################
-install: install-whois install-mkpasswd install-pos
+install: install-whois install-mkpasswd install-pos install-bashcomp
 
 install-whois: whois
 	$(INSTALL) -d $(BASEDIR)$(prefix)/bin/
@@ -140,6 +142,11 @@ install-mkpasswd: mkpasswd
 install-pos:
 	cd po && $(MAKE) install
 
+install-bashcomp:
+	$(INSTALL) -d $(BASEDIR)$(BASHCOMPDIR)
+	$(INSTALL) -m 0644 mkpasswd.bash $(BASEDIR)$(BASHCOMPDIR)/mkpasswd
+	$(INSTALL) -m 0644 whois.bash $(BASEDIR)$(BASHCOMPDIR)/whois
+
 distclean: clean
 	rm -f version.h po/whois.pot
 
diff --git a/mkpasswd.bash b/mkpasswd.bash
new file mode 100644
index 0000000..2d0b9a6
--- /dev/null
+++ b/mkpasswd.bash
@@ -0,0 +1,33 @@
+_mkpasswd() {
+
+	case $3 in
+	--help | --version | --salt | --rounds | --password-fd | -[hVSRP])
+		return 0
+		;;
+	--method | -m)
+		COMPREPLY=($(compgen -W '$(
+			LC_ALL=C "$1" --method=help 2>/dev/null |
+				while read -r method _; do
+					[[ $method == Available ]] ||
+						printf "%s\n" "$method"
+				done
+			)'))
+		return 0
+		;;
+	esac
+
+	if [[ $2 == -* ]]; then
+		COMPREPLY=($(compgen -W '
+			--method
+			-5
+			--salt
+			--rounds
+			--password-fd
+			--stdin
+			--help
+			--version
+		' -- "$2"))
+		return 0
+	fi
+
+} && complete -F _mkpasswd mkpasswd
diff --git a/whois.bash b/whois.bash
new file mode 100644
index 0000000..1f7291f
--- /dev/null
+++ b/whois.bash
@@ -0,0 +1,86 @@
+_whois_query() {
+	"$1" -q "$2" 2>/dev/null | while read -r item _; do
+		[[ $item == %* ]] && continue
+		printf "%s\n" "${item%%:*}"
+	done
+}
+
+_whois_hosts() {
+	# _known_hosts_real from github.com/scop/bash-completion if available
+	if declare -f _known_hosts_real &>/dev/null; then
+		_known_hosts_real -- "$1"
+		return 0
+	fi
+	COMPREPLY=($(compgen -A hostname -- "$1"))
+}
+
+_whois() {
+
+	case $3 in
+	--help | --version | -p | --port | -i)
+		return 0
+		;;
+	-h | --host)
+		_whois_hosts "$2"
+		return 0
+		;;
+	-T | -t | -v)
+		[[ ${_whois_types-} ]] ||
+			_whois_types=" $(_whois_query "$1" types)"
+		COMPREPLY=($(compgen -W '$_whois_types' -- "$2"))
+		return 0
+		;;
+	-s | -g)
+		[[ ${_whois_sources-} ]] ||
+			_whois_sources=" $(_whois_query "$1" sources)"
+		COMPREPLY=($(compgen -W '$_whois_sources' -- "$2"))
+		if [[ $3 == -g ]]; then
+			[[ ${#COMPREPLY[*]} -eq 1 ]] && COMPREPLY[0]+=:
+			compopt -o nospace
+		fi
+		return 0
+		;;
+	-q)
+		COMPREPLY=($(compgen -W 'version sources types' -- "$2"))
+		return 0
+		;;
+	esac
+
+	if [[ $2 == -* ]]; then
+		COMPREPLY=($(compgen -W '
+			-h --host
+			-p --port
+			-I
+			-H
+			--verbose
+			--no-recursion
+			--help
+			--version
+			-l
+			-L
+			-m
+			-M
+			-c
+			-x
+			-b
+			-B
+			-G
+			-d
+			-i
+			-T
+			-K
+			-r
+			-R
+			-a
+			-s
+			-g
+			-t
+			-v
+			-q
+		' -- "$2"))
+		return 0
+	fi
+
+	_whois_hosts "$2"
+
+} && complete -F _whois whois