diff --git a/src/libostree/ostree-repo.c b/src/libostree/ostree-repo.c
index 0346a3df..8affec53 100644
--- a/src/libostree/ostree-repo.c
+++ b/src/libostree/ostree-repo.c
@@ -3324,11 +3324,6 @@ out:
  * @self: Self
  * @from_commit: SHA256 of starting commit to sign, or %NULL
  * @to_commit: SHA256 of target commit to sign
- * @key_id: Use this GPG key id
- * @homedir: (allow-none): GPG home directory, or %NULL
- * @cancellable: A #GCancellable
- * @error: a #GError
- *
  * This function is deprecated, sign the summary file instead.
  * Add a GPG signature to a static delta.
  */
@@ -3345,7 +3340,80 @@ ostree_repo_sign_delta (OstreeRepo     *self,
   return FALSE;
 }
 
- OstreeGpgVerifyResult *
+/**
+ * ostree_repo_add_gpg_signature_summary:
+ * @self: Self
+ * @key_id: NULL-terminated array of GPG keys.
+ * @homedir: (allow-none): GPG home directory, or %NULL
+ * @cancellable: A #GCancellable
+ * @error: a #GError
+ *
+ * Add a GPG signature to a static delta.
+ */
+gboolean
+ostree_repo_add_gpg_signature_summary (OstreeRepo     *self,
+                                       const gchar    **key_id,
+                                       const gchar    *homedir,
+                                       GCancellable   *cancellable,
+                                       GError        **error)
+{
+  gboolean ret = FALSE;
+  g_autoptr(GBytes) summary_data = NULL;
+  g_autoptr(GFile) summary_file = NULL;
+  g_autoptr(GFile) signature_path = NULL;
+  GError *temp_error = NULL;
+  g_autoptr(GVariant) existing_signatures = NULL;
+  g_autoptr(GVariant) new_metadata = NULL;
+  g_autoptr(GVariant) normalized = NULL;
+  guint i;
+  signature_path = g_file_resolve_relative_path (self->repodir, "summary.sig");
+
+  summary_file = g_file_resolve_relative_path (self->repodir, "summary");
+  summary_data = gs_file_map_readonly (summary_file, cancellable, error);
+  if (!summary_data)
+    goto out;
+
+  if (!ot_util_variant_map (signature_path, G_VARIANT_TYPE ("a{sv}"),
+                            TRUE, &existing_signatures, &temp_error))
+    {
+      if (g_error_matches (temp_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
+        {
+          g_clear_error (&temp_error);
+        }
+      else
+        {
+          g_propagate_error (error, temp_error);
+          goto out;
+        }
+    }
+
+  for (i = 0; key_id[i]; i++)
+    {
+      g_autoptr(GBytes) signature_data = NULL;
+      if (!sign_data (self, summary_data, key_id[i], homedir,
+                      &signature_data,
+                      cancellable, error))
+        goto out;
+
+      new_metadata = _ostree_detached_metadata_append_gpg_sig (existing_signatures, signature_data);
+    }
+
+  normalized = g_variant_get_normal_form (new_metadata);
+
+  if (!_ostree_repo_file_replace_contents (self,
+                                           self->repo_dir_fd,
+                                           "summary.sig",
+                                           g_variant_get_data (normalized),
+                                           g_variant_get_size (normalized),
+                                           cancellable, error))
+    goto out;
+
+  ret = TRUE;
+ out:
+  return ret;
+}
+
+OstreeGpgVerifyResult *
 _ostree_repo_gpg_verify_with_metadata (OstreeRepo          *self,
                                        GBytes              *signed_data,
                                        GVariant            *metadata,
diff --git a/src/libostree/ostree-repo.h b/src/libostree/ostree-repo.h
index c882356a..92bddd48 100644
--- a/src/libostree/ostree-repo.h
+++ b/src/libostree/ostree-repo.h
@@ -712,6 +712,13 @@ gboolean ostree_repo_sign_delta (OstreeRepo     *self,
                                  GCancellable   *cancellable,
                                  GError        **error);
 
+gboolean
+ostree_repo_add_gpg_signature_summary (OstreeRepo     *self,
+                                       const gchar    **key_id,
+                                       const gchar    *homedir,
+                                       GCancellable   *cancellable,
+                                       GError        **error);
+
 gboolean ostree_repo_append_gpg_signature (OstreeRepo     *self,
                                            const gchar    *commit_checksum,
                                            GBytes         *signature_bytes,