diff --git a/app/manifest_add_digests_cmd.go b/app/manifest_add_digests_cmd.go
index d1da1f9f..12029d05 100644
--- a/app/manifest_add_digests_cmd.go
+++ b/app/manifest_add_digests_cmd.go
@@ -10,7 +10,7 @@ import (
 )
 
 type addDigestsCmd struct {
-	Manifest []string `arg:"" help:"List of files that need to be updated with digests"`
+	Manifest []string `arg:"" type:"existingfile" help:"List of files that need to be updated with digests" predictor:"hclfile"`
 }
 
 func (*addDigestsCmd) Help() string {
diff --git a/app/test_cmd.go b/app/test_cmd.go
index dd250175..bcbb3e38 100644
--- a/app/test_cmd.go
+++ b/app/test_cmd.go
@@ -8,7 +8,7 @@ import (
 )
 
 type testCmd struct {
-	Pkg          []manifest.GlobSelector `arg:"" required:"" help:"Run sanity tests for these packages."`
+	Pkg          []manifest.GlobSelector `arg:"" required:"" help:"Run sanity tests for these packages." predictor:"package"`
 	CheckSources bool                    `help:"Check that package sources are reachable" default:"true" negatable:""`
 }