diff --git a/core/apiauth/signer.go b/core/apiauth/signer.go
index a2c21f39f..e4814d3c8 100644
--- a/core/apiauth/signer.go
+++ b/core/apiauth/signer.go
@@ -3,7 +3,9 @@ package apiauth
 import (
 	"cmp"
 	"context"
+	"crypto/rand"
 	"crypto/sha256"
+	"encoding/hex"
 	"errors"
 	"fmt"
 	"strings"
@@ -15,7 +17,6 @@ import (
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/model/id"
 	"github.com/navidrome/navidrome/utils"
 )
 
@@ -59,7 +60,7 @@ func loadSigner(ctx context.Context, ds model.DataStore, now func() time.Time) (
 }
 
 func loadKey(ctx context.Context, ds model.DataStore) (string, error) {
-	enc, err := utils.Encrypt(ctx, encryptionKey(), id.NewRandom())
+	enc, err := utils.Encrypt(ctx, encryptionKey(), newKey())
 	if err != nil {
 		return "", fmt.Errorf("encrypting API v1 key: %w", err)
 	}
@@ -98,6 +99,13 @@ func loadKey(ctx context.Context, ds model.DataStore) (string, error) {
 	return key, nil
 }
 
+// newKey returns 256 random bits, the minimum RFC 7518 asks of an HS256 key.
+func newKey() string {
+	b := make([]byte, 32)
+	_, _ = rand.Read(b) // never fails since Go 1.24
+	return hex.EncodeToString(b)
+}
+
 func encryptionKey() []byte {
 	sum := sha256.Sum256([]byte(cmp.Or(conf.Server.PasswordEncryptionKey, consts.DefaultEncryptionKey)))
 	return sum[:]
diff --git a/core/apiauth/signer_test.go b/core/apiauth/signer_test.go
index acb197dde..b749d6193 100644
--- a/core/apiauth/signer_test.go
+++ b/core/apiauth/signer_test.go
@@ -2,12 +2,14 @@ package apiauth
 
 import (
 	"context"
+	"encoding/hex"
 	"sync"
 	"time"
 
 	"github.com/lestrrat-go/jwx/v3/jwt"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
@@ -23,6 +25,21 @@ var _ = Describe("signer", func() {
 		Expect(realDS.Property().Delete(ctx, consts.JWTAPIv1SecretKey)).To(Or(Succeed(), MatchError(model.ErrNotFound)))
 	})
 
+	It("creates a 256-bit key", func() {
+		key, err := loadKey(ctx, realDS)
+		Expect(err).ToNot(HaveOccurred())
+		raw, err := hex.DecodeString(key)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(raw).To(HaveLen(32))
+	})
+
+	It("keeps using a stored key created in the older format", func() {
+		enc, err := utils.Encrypt(ctx, encryptionKey(), "legacy22charskeyABCDEF")
+		Expect(err).ToNot(HaveOccurred())
+		Expect(realDS.Property().Put(ctx, consts.JWTAPIv1SecretKey, enc)).To(Succeed())
+		Expect(loadKey(ctx, realDS)).To(Equal("legacy22charskeyABCDEF"))
+	})
+
 	It("round-trips claims", func() {
 		s, err := loadSigner(ctx, realDS, clock)
 		Expect(err).ToNot(HaveOccurred())