diff --git a/ChangeLog b/ChangeLog
index fafc9e9e3..626b0d970 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2018-06-03  Oliver Kiddle  <okiddle@yahoo.co.uk>
 
+	* 42922: dana: Completion/Unix/Command/_tac: new tac completion
+
 	* 42881: Completion/Unix/Command/_ghostscript: update options in
 	ghostscript completion and query more matches directly from it
 
diff --git a/Completion/Unix/Command/_tac b/Completion/Unix/Command/_tac
new file mode 100644
index 000000000..7a15bffff
--- /dev/null
+++ b/Completion/Unix/Command/_tac
@@ -0,0 +1,19 @@
+#compdef tac gtac
+
+local variant
+
+_pick_variant -r variant gnu='Free Soft' unix --version
+
+# NetBSD (at least) has its own bare-bones version of this tool
+[[ $variant == gnu ]] || {
+  _default
+  return
+}
+
+_arguments -s -S : \
+  '(: -)--help[display help information]' \
+  '(: -)--version[display version information]' \
+  '(-b --before)'{-b,--before}'[attach separator before instead of after]' \
+  '(-r --regex)'{-r,--regex}'[treat separator as regular expression (with -s)]' \
+  '(-s --separator)'{-s+,--separator=}'[use specified separator instead of newline]:separator' \
+  '*: :_files'