diff --git a/completions-core/Makefile.am b/completions-core/Makefile.am
index abcd93aea21..39d407e21ff 100644
--- a/completions-core/Makefile.am
+++ b/completions-core/Makefile.am
@@ -82,6 +82,7 @@ cross_platform = 2to3.bash \
 		dmypy.bash \
 		dnssec-keygen.bash \
 		dnsspoof.bash \
+		doas.bash \
 		dot.bash \
 		dpkg.bash \
 		dpkg-source.bash \
diff --git a/completions-core/doas.bash b/completions-core/doas.bash
new file mode 100644
index 00000000000..43a3d2a999d
--- /dev/null
+++ b/completions-core/doas.bash
@@ -0,0 +1,46 @@
+# doas(1) completion
+
+_comp_cmd_doas()
+{
+    local cur prev words cword was_split comp_args
+    _comp_initialize -s -- "$@" || return
+
+    local noargopts='!(-*|*[uCLs]*)'
+
+    local i
+    for ((i = 1; i <= cword; i++)); do
+        if [[ ${words[i]} != -* ]]; then
+            local PATH=$PATH:/sbin:/usr/sbin:/usr/local/sbin
+            local root_command=${words[i]}
+            local _comp_root_command=$1
+            _comp_command_offset "$i"
+            return
+        fi
+        [[ ${words[i]} == -@(${noargopts}[uCLs]) ]] &&
+            ((i++))
+    done
+
+    # shellcheck disable=SC2254 # glob $noargopts should not be quoted
+    case $prev in
+        -${noargopts}u)
+            _comp_compgen -- -u
+            return
+            ;;
+        -${noargopts}C)
+            _comp_compgen_filedir
+            return
+            ;;
+        -${noargopts}[Ls])
+            return
+            ;;
+    esac
+
+    [[ $was_split ]] && return
+
+    if [[ $cur == -* ]]; then
+        _comp_compgen_usage
+        [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
+        return
+    fi
+} &&
+    complete -F _comp_cmd_doas doas
diff --git a/test/t/Makefile.am b/test/t/Makefile.am
index 115f5736f10..b0736686f87 100644
--- a/test/t/Makefile.am
+++ b/test/t/Makefile.am
@@ -140,6 +140,7 @@ EXTRA_DIST = \
 	test_dmypy.py \
 	test_dnssec_keygen.py \
 	test_dnsspoof.py \
+	test_doas.py \
 	test_dot.py \
 	test_dpkg.py \
 	test_dpkg_deb.py \
diff --git a/test/t/test_doas.py b/test/t/test_doas.py
new file mode 100644
index 00000000000..a8039c58608
--- /dev/null
+++ b/test/t/test_doas.py
@@ -0,0 +1,17 @@
+import pytest
+
+
+class TestDoas:
+    @pytest.mark.complete("doas -", require_cmd=True)
+    def test_1(self, completion):
+        assert completion
+
+    @pytest.mark.complete("doas cd foo", cwd="shared/default")
+    def test_2(self, completion):
+        assert completion == ".d/"
+        assert not completion.endswith(" ")
+
+    @pytest.mark.complete("doas sh share")
+    def test_3(self, completion):
+        assert completion == "d/"
+        assert not completion.endswith(" ")
diff --git a/test/test-cmd-list.txt b/test/test-cmd-list.txt
index bec7631b8d2..004c0153633 100644
--- a/test/test-cmd-list.txt
+++ b/test/test-cmd-list.txt
@@ -79,6 +79,7 @@ display
 dmesg
 dmypy
 dnsspoof
+doas
 dpkg
 dpkg-deb
 dpkg-query