diff --git a/cmd/restic/cmd_debug.go b/cmd/restic/cmd_debug.go
index 0a0b43295..efc022941 100644
--- a/cmd/restic/cmd_debug.go
+++ b/cmd/restic/cmd_debug.go
@@ -7,7 +7,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"sync"
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
@@ -18,7 +17,6 @@ import (
 	"github.com/restic/restic/internal/repository"
 	"github.com/restic/restic/internal/restic"
 	"github.com/restic/restic/internal/ui"
-	"github.com/restic/restic/internal/ui/progress"
 )
 
 func registerDebugCommand(cmd *cobra.Command, globalOptions *global.Options) {
@@ -118,50 +116,6 @@ func debugPrintSnapshots(ctx context.Context, repo *repository.Repository, wr io
 	})
 }
 
-// Pack is the struct used in printPacks.
-type Pack struct {
-	Name string `json:"name"`
-
-	Blobs []Blob `json:"blobs"`
-}
-
-// Blob is the struct used in printPacks.
-type Blob struct {
-	Type   restic.BlobType `json:"type"`
-	Length uint            `json:"length"`
-	ID     restic.ID       `json:"id"`
-	Offset uint            `json:"offset"`
-}
-
-func printPacks(ctx context.Context, repo *repository.Repository, wr io.Writer, printer progress.Printer) error {
-
-	var m sync.Mutex
-	return restic.ParallelList(ctx, repo, restic.PackFile, repo.Connections(), func(ctx context.Context, id restic.ID, size int64) error {
-		blobs, err := repo.ListPack(ctx, id, size)
-		if err != nil {
-			printer.E("error for pack %v: %v", id.Str(), err)
-			return nil
-		}
-
-		p := Pack{
-			Name:  id.String(),
-			Blobs: make([]Blob, len(blobs)),
-		}
-		for i, blob := range blobs {
-			p.Blobs[i] = Blob{
-				Type:   blob.Type,
-				Length: blob.Length,
-				ID:     blob.ID,
-				Offset: blob.Offset,
-			}
-		}
-
-		m.Lock()
-		defer m.Unlock()
-		return prettyPrintJSON(wr, p)
-	})
-}
-
 func runDebugDump(ctx context.Context, gopts global.Options, args []string, term ui.Terminal) error {
 	printer := ui.NewProgressPrinter(false, gopts.Verbosity, term)
 
@@ -183,7 +137,7 @@ func runDebugDump(ctx context.Context, gopts global.Options, args []string, term
 	case "snapshots":
 		return debugPrintSnapshots(ctx, repo, gopts.Term.OutputWriter())
 	case "packs":
-		return printPacks(ctx, repo, gopts.Term.OutputWriter(), printer)
+		return repository.DumpPacks(ctx, repo, gopts.Term.OutputWriter(), printer)
 	case "all":
 		printer.S("snapshots:")
 		err := debugPrintSnapshots(ctx, repo, gopts.Term.OutputWriter())
diff --git a/internal/repository/debug.go b/internal/repository/debug.go
index fd6533a82..c3d5bfcd5 100644
--- a/internal/repository/debug.go
+++ b/internal/repository/debug.go
@@ -6,10 +6,12 @@ import (
 	"context"
 	"crypto/aes"
 	"crypto/cipher"
+	"encoding/json"
 	"fmt"
 	"io"
 	"os"
 	"runtime"
+	"sync"
 	"time"
 
 	"github.com/klauspost/compress/zstd"
@@ -22,6 +24,56 @@ import (
 	"github.com/restic/restic/internal/ui/progress"
 )
 
+type packDumpEntry struct {
+	Name  string         `json:"name"`
+	Blobs []packDumpBlob `json:"blobs"`
+}
+
+type packDumpBlob struct {
+	Type   restic.BlobType `json:"type"`
+	Length uint            `json:"length"`
+	ID     restic.ID       `json:"id"`
+	Offset uint            `json:"offset"`
+}
+
+func writePackDumpJSON(wr io.Writer, item any) error {
+	buf, err := json.MarshalIndent(item, "", "  ")
+	if err != nil {
+		return err
+	}
+	_, err = wr.Write(append(buf, '\n'))
+	return err
+}
+
+// DumpPacks lists each pack file and writes its header blob layout as JSON to wr.
+func DumpPacks(ctx context.Context, repo *Repository, wr io.Writer, printer progress.Printer) error {
+	var m sync.Mutex
+	return restic.ParallelList(ctx, repo, restic.PackFile, repo.Connections(), func(ctx context.Context, id restic.ID, size int64) error {
+		blobs, err := repo.ListPack(ctx, id, size)
+		if err != nil {
+			printer.E("error for pack %v: %v", id.Str(), err)
+			return nil
+		}
+
+		p := packDumpEntry{
+			Name:  id.String(),
+			Blobs: make([]packDumpBlob, len(blobs)),
+		}
+		for i, blob := range blobs {
+			p.Blobs[i] = packDumpBlob{
+				Type:   blob.Type,
+				Length: blob.Length,
+				ID:     blob.ID,
+				Offset: blob.Offset,
+			}
+		}
+
+		m.Lock()
+		defer m.Unlock()
+		return writePackDumpJSON(wr, p)
+	})
+}
+
 // DumpIndexes loads each on-disk index file and writes its debug dump to wr.
 func DumpIndexes(ctx context.Context, repo restic.ListerLoaderUnpacked, wr io.Writer, printer progress.Printer) error {
 	return index.ForAllIndexes(ctx, repo, repo, func(id restic.ID, idx *index.Index, err error) error {