diff --git a/completers/cfdisk_completer/cmd/root.go b/completers/cfdisk_completer/cmd/root.go
index d0640ee5c0..22ada700fa 100644
--- a/completers/cfdisk_completer/cmd/root.go
+++ b/completers/cfdisk_completer/cmd/root.go
@@ -39,8 +39,9 @@ func init() {
 
 func ActionBlockDevicesAndFiles() carapace.Action {
 	return carapace.ActionCallback(func(c carapace.Context) carapace.Action {
-		blockDevices := fs.ActionBlockDevices().Invoke(c)
-		files := carapace.ActionFiles().Invoke(c)
-		return blockDevices.Merge(files).ToA()
+		return carapace.Batch(
+			fs.ActionBlockDevices(),
+			carapace.ActionFiles(),
+		).Invoke(c).Merge().ToA()
 	})
 }
diff --git a/completers/fdisk_completer/cmd/root.go b/completers/fdisk_completer/cmd/root.go
index c5333bd1f7..d4e3b9b9c7 100644
--- a/completers/fdisk_completer/cmd/root.go
+++ b/completers/fdisk_completer/cmd/root.go
@@ -69,8 +69,9 @@ func init() {
 
 func ActionBlockDevicesAndFiles() carapace.Action {
 	return carapace.ActionCallback(func(c carapace.Context) carapace.Action {
-		blockDevices := fs.ActionBlockDevices().Invoke(c)
-		files := carapace.ActionFiles().Invoke(c)
-		return blockDevices.Merge(files).ToA()
+		return carapace.Batch(
+			fs.ActionBlockDevices(),
+			carapace.ActionFiles(),
+		).Invoke(c).Merge().ToA()
 	})
 }
diff --git a/completers/flutter_completer/cmd/root.go b/completers/flutter_completer/cmd/root.go
index 403e55136b..855ffec227 100644
--- a/completers/flutter_completer/cmd/root.go
+++ b/completers/flutter_completer/cmd/root.go
@@ -26,9 +26,10 @@ func init() {
 
 	carapace.Gen(rootCmd).FlagCompletion(carapace.ActionMap{
 		"device-id": carapace.ActionCallback(func(c carapace.Context) carapace.Action {
-			devices := action.ActionDevices().Invoke(c)
-			emulators := action.ActionEmulators().Invoke(c)
-			return devices.Merge(emulators).ToA()
+			return carapace.Batch(
+				action.ActionDevices(),
+				action.ActionEmulators(),
+			).Invoke(c).Merge().ToA()
 		}),
 	})
 }
diff --git a/completers/gh_completer/cmd/pr_checks.go b/completers/gh_completer/cmd/pr_checks.go
index ed9b76761b..0fcffbcf05 100644
--- a/completers/gh_completer/cmd/pr_checks.go
+++ b/completers/gh_completer/cmd/pr_checks.go
@@ -18,9 +18,10 @@ func init() {
 
 	carapace.Gen(pr_checksCmd).PositionalCompletion(
 		carapace.ActionCallback(func(c carapace.Context) carapace.Action {
-			pullRequests := action.ActionPullRequests(pr_checksCmd, action.PullRequestOpts{Open: true}).Invoke(c)
-			branches := action.ActionBranches(pr_checksCmd).Invoke(c)
-			return pullRequests.Merge(branches).ToA()
+			return carapace.Batch(
+				action.ActionPullRequests(pr_checksCmd, action.PullRequestOpts{Open: true}),
+				action.ActionBranches(pr_checksCmd),
+			).Invoke(c).Merge().ToA()
 		}),
 	)
 }
diff --git a/completers/glab_completer/cmd/action/mergeRequest.go b/completers/glab_completer/cmd/action/mergeRequest.go
index fab4096bb9..e7ff8d1a9f 100644
--- a/completers/glab_completer/cmd/action/mergeRequest.go
+++ b/completers/glab_completer/cmd/action/mergeRequest.go
@@ -34,8 +34,9 @@ func ActionMergeRequests(cmd *cobra.Command, state string) carapace.Action {
 
 func ActionMergeRequestsAndBranches(cmd *cobra.Command, state string) carapace.Action {
 	return carapace.ActionCallback(func(c carapace.Context) carapace.Action {
-		branches := ActionBranches(cmd).Invoke(c)
-		mergeRequests := ActionMergeRequests(cmd, state).Invoke(c)
-		return branches.Merge(mergeRequests).Filter(c.Args).ToA()
+		return carapace.Batch(
+			ActionBranches(cmd),
+			ActionMergeRequests(cmd, state),
+		).Invoke(c).Merge().ToA()
 	})
 }
diff --git a/completers/glab_completer/cmd/action/repoOverride.go b/completers/glab_completer/cmd/action/repoOverride.go
index 16315059dc..f1aaf971d3 100644
--- a/completers/glab_completer/cmd/action/repoOverride.go
+++ b/completers/glab_completer/cmd/action/repoOverride.go
@@ -31,16 +31,17 @@ func ActionRepo(cmd *cobra.Command) carapace.Action {
 			case 0:
 				return carapace.ActionValues(configHosts...).Invoke(c).Suffix("/").ToA()
 			case 1:
-				// TODO goroutine
-				users := ActionUsers(cmd).Invoke(c).Suffix("/")
-				groups := ActionGroups(cmd).Invoke(c).Suffix("/")
-				return users.Merge(groups).ToA()
+				return carapace.Batch(
+					ActionUsers(cmd),
+					ActionGroups(cmd),
+				).Invoke(c).Merge().Suffix("/").ToA()
 			case 2:
-				// TODO goroutine
-				subgroups := ActionSubgroups(cmd, c.Parts[1]).Invoke(c).Suffix("/")
-				groupProjects := ActionGroupProjects(cmd, c.Parts[1]).Invoke(c)
-				userProjects := ActionUserProjects(cmd, c.Parts[1]).Invoke(c)
-				return subgroups.Merge(groupProjects, userProjects).ToA()
+				b := carapace.Batch(
+					ActionSubgroups(cmd, c.Parts[1]),
+					ActionGroupProjects(cmd, c.Parts[1]),
+					ActionUserProjects(cmd, c.Parts[1]),
+				).Invoke(c)
+				return b[0].Suffix("/").Merge(b[1:]...).ToA() // ActionSubgroups needs `/` suffix
 			case 3:
 				groupProjects := ActionGroupProjects(cmd, strings.Join(c.Parts[1:], "/")).Invoke(c)
 				return groupProjects.ToA()
diff --git a/completers/glab_completer/cmd/repo_archive.go b/completers/glab_completer/cmd/repo_archive.go
index ba80819941..0954811805 100644
--- a/completers/glab_completer/cmd/repo_archive.go
+++ b/completers/glab_completer/cmd/repo_archive.go
@@ -20,9 +20,10 @@ func init() {
 	carapace.Gen(repo_archiveCmd).FlagCompletion(carapace.ActionMap{
 		"format": carapace.ActionValues("tar.gz", "tar.bz2", "tbz", "tbz2", "tb2", "bz2", "tar", "zip"),
 		"sha": carapace.ActionCallback(func(c carapace.Context) carapace.Action {
-			branches := action.ActionBranches(repo_archiveCmd).Invoke(c)
-			tags := action.ActionTags(repo_archiveCmd).Invoke(c)
-			return branches.Merge(tags).ToA() // TODO sha
+			return carapace.Batch(
+				action.ActionBranches(repo_archiveCmd),
+				action.ActionTags(repo_archiveCmd),
+			).Invoke(c).Merge().ToA() // TODO sha
 		}),
 	})
 
diff --git a/completers/java_completer/cmd/root.go b/completers/java_completer/cmd/root.go
index 30e3702512..25e05a786e 100644
--- a/completers/java_completer/cmd/root.go
+++ b/completers/java_completer/cmd/root.go
@@ -220,14 +220,13 @@ func ActionClasspathClasses(cmd *cobra.Command) carapace.Action {
 			}
 		}
 
-		actions := carapace.ActionValues().Invoke(c)
+		actions := make([]carapace.Action, 0)
 		for _, file := range files {
 			if strings.HasSuffix(file, ".jar") ||
 				strings.HasSuffix(file, ".zip") {
-				a := action.ActionJarFileClasses(file)
-				actions = actions.Merge(a.Invoke(c))
+				actions = append(actions, action.ActionJarFileClasses(file))
 			}
 		}
-		return actions.ToMultiPartsA(".")
+		return carapace.Batch(actions...).Invoke(c).Merge().ToMultiPartsA(".")
 	})
 }
diff --git a/completers/kill_completer/cmd/root.go b/completers/kill_completer/cmd/root.go
index c85ecb07fe..d2c3049fef 100644
--- a/completers/kill_completer/cmd/root.go
+++ b/completers/kill_completer/cmd/root.go
@@ -54,8 +54,9 @@ func init() {
 
 func actionProcessIdsAndNames() carapace.Action {
 	return carapace.ActionCallback(func(c carapace.Context) carapace.Action {
-		pids := os.ActionProcessIds().Invoke(c)
-		names := os.ActionProcessExecutables().Invoke(c)
-		return pids.Merge(names).Filter(c.Args).ToA()
+		return carapace.Batch(
+			os.ActionProcessIds(),
+			os.ActionProcessExecutables(),
+		).Invoke(c).Merge().Filter(c.Args).ToA()
 	})
 }
diff --git a/completers/pandoc_completer/cmd/action/format.go b/completers/pandoc_completer/cmd/action/format.go
index c0b751bef7..1d0e5be5a4 100644
--- a/completers/pandoc_completer/cmd/action/format.go
+++ b/completers/pandoc_completer/cmd/action/format.go
@@ -53,9 +53,10 @@ func extensionFields(s string) []string {
 
 func ActionFormats() carapace.Action {
 	return carapace.ActionCallback(func(c carapace.Context) carapace.Action {
-		input := ActionInputFormats().Invoke(c)
-		output := ActionOutputFormats().Invoke(c)
-		return input.Merge(output).ToA()
+		return carapace.Batch(
+			ActionInputFormats(),
+			ActionOutputFormats(),
+		).Invoke(c).Merge().ToA()
 	})
 }
 
diff --git a/go.mod b/go.mod
index 739aace1e4..feab13bd7e 100644
--- a/go.mod
+++ b/go.mod
@@ -6,7 +6,7 @@ require (
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/mitchellh/go-ps v1.0.0
 	github.com/pelletier/go-toml v1.8.1
-	github.com/rsteube/carapace v0.7.1
+	github.com/rsteube/carapace v0.8.0
 	github.com/spf13/cobra v1.1.1
 	github.com/spf13/pflag v1.0.5
 	golang.org/x/sys v0.0.0-20210426230700-d19ff857e887
diff --git a/go.sum b/go.sum
index 8f9354ab27..2b43cf4e16 100644
--- a/go.sum
+++ b/go.sum
@@ -148,8 +148,8 @@ github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7z
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
-github.com/rsteube/carapace v0.7.1 h1:HfD0MgX8HtrhEqfodE+XAWogAF35UdisWxDiblLi7bA=
-github.com/rsteube/carapace v0.7.1/go.mod h1:Vo7qSmFjuOTjB3cEyyat0+ANvVHlS0HR4NhIdAN07vM=
+github.com/rsteube/carapace v0.8.0 h1:OVTWIqLmE9qskAtFOIvYvDNmB+6fL3Ovxe5y78iBXQ8=
+github.com/rsteube/carapace v0.8.0/go.mod h1:Vo7qSmFjuOTjB3cEyyat0+ANvVHlS0HR4NhIdAN07vM=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=