diff --git a/src/daemon/org.projectatomic.rpmostree1.policy b/src/daemon/org.projectatomic.rpmostree1.policy
index 8f180d3e74..64775321bf 100644
--- a/src/daemon/org.projectatomic.rpmostree1.policy
+++ b/src/daemon/org.projectatomic.rpmostree1.policy
@@ -138,6 +138,17 @@
     </defaults>
   </action>
 
+  <action id="org.projectatomic.rpmostree1.repo-modify">
+    <description>Modify repository settings</description>
+    <message>Authentication is required to modify repository settings</message>
+    <icon_name>package-x-generic</icon_name>
+    <defaults>
+      <allow_any>auth_admin</allow_any>
+      <allow_inactive>auth_admin</allow_inactive>
+      <allow_active>auth_admin_keep</allow_active>
+    </defaults>
+  </action>
+
   <action id="org.projectatomic.rpmostree1.client-management">
     <description>Register and unregister as a sysroot client</description>
     <message>Authentication is required to register as a sysroot client</message>
diff --git a/src/daemon/org.projectatomic.rpmostree1.xml b/src/daemon/org.projectatomic.rpmostree1.xml
index 933e11c955..6ae04a4590 100644
--- a/src/daemon/org.projectatomic.rpmostree1.xml
+++ b/src/daemon/org.projectatomic.rpmostree1.xml
@@ -281,6 +281,13 @@
       <arg type="s" name="transaction_address" direction="out"/>
     </method>
 
+    <!-- Set options in yum .repo files -->
+    <method name="ModifyYumRepo">
+      <arg type="s" name="repo_id" direction="in"/>
+      <arg type="a{ss}" name="settings" direction="in"/>
+      <arg type="s" name="transaction_address" direction="out"/>
+    </method>
+
     <!-- Available modifiers:
          "set-refspec" (type 's')
          "set-revision" (type 's')
diff --git a/src/daemon/rpmostreed-os.c b/src/daemon/rpmostreed-os.c
index 9da373282e..915947b3ec 100644
--- a/src/daemon/rpmostreed-os.c
+++ b/src/daemon/rpmostreed-os.c
@@ -111,6 +111,10 @@ os_authorize_method (GDBusInterfaceSkeleton *interface,
     {
       g_ptr_array_add (actions, "org.projectatomic.rpmostree1.repo-refresh");
     }
+  else if (g_strcmp0 (method_name, "ModifyYumRepo") == 0)
+    {
+      g_ptr_array_add (actions, "org.projectatomic.rpmostree1.repo-modify");
+    }
   else if (g_strcmp0 (method_name, "Deploy") == 0)
     {
       g_ptr_array_add (actions, "org.projectatomic.rpmostree1.deploy");
@@ -916,6 +920,60 @@ os_handle_refresh_md (RPMOSTreeOS *interface,
   return TRUE;
 }
 
+static gboolean
+os_handle_modify_yum_repo (RPMOSTreeOS *interface,
+                           GDBusMethodInvocation *invocation,
+                           const char *arg_repo_id,
+                           GVariant *arg_settings)
+{
+  glnx_unref_object OstreeSysroot *ot_sysroot = NULL;
+  g_autoptr(GCancellable) cancellable = g_cancellable_new ();
+  const char *osname;
+  GError *local_error = NULL;
+
+  /* try to merge with an existing transaction, otherwise start a new one */
+  glnx_unref_object RpmostreedTransaction *transaction = NULL;
+  RpmostreedSysroot *rsysroot = rpmostreed_sysroot_get ();
+  if (!rpmostreed_sysroot_prep_for_txn (rsysroot, invocation, &transaction, &local_error))
+    goto out;
+  if (transaction)
+    goto out;
+
+  if (!rpmostreed_sysroot_load_state (rpmostreed_sysroot_get (),
+                                      cancellable,
+                                      &ot_sysroot,
+                                      NULL,
+                                      &local_error))
+    goto out;
+
+  osname = rpmostree_os_get_name (interface);
+
+  transaction = rpmostreed_transaction_new_modify_yum_repo (invocation,
+                                                            ot_sysroot,
+                                                            osname,
+                                                            arg_repo_id,
+                                                            arg_settings,
+                                                            cancellable,
+                                                            &local_error);
+  if (transaction == NULL)
+    goto out;
+
+  rpmostreed_sysroot_set_txn (rsysroot, transaction);
+
+out:
+  if (local_error != NULL)
+    {
+      g_dbus_method_invocation_take_error (invocation, local_error);
+    }
+  else
+    {
+      const char *client_address = rpmostreed_transaction_get_client_address (transaction);
+      rpmostree_os_complete_modify_yum_repo (interface, invocation, client_address);
+    }
+
+  return TRUE;
+}
+
 /* This is an older variant of Cleanup, kept for backcompat */
 static gboolean
 os_handle_clear_rollback_target (RPMOSTreeOS *interface,
@@ -1668,6 +1726,7 @@ rpmostreed_os_iface_init (RPMOSTreeOSIface *iface)
   iface->handle_get_deployment_boot_config = os_handle_get_deployment_boot_config;
   iface->handle_kernel_args                = os_handle_kernel_args;
   iface->handle_refresh_md                 = os_handle_refresh_md;
+  iface->handle_modify_yum_repo            = os_handle_modify_yum_repo;
   iface->handle_rollback                   = os_handle_rollback;
   iface->handle_set_initramfs_state        = os_handle_set_initramfs_state;
   iface->handle_update_deployment          = os_handle_update_deployment;
diff --git a/src/daemon/rpmostreed-transaction-types.c b/src/daemon/rpmostreed-transaction-types.c
index e817d25d6c..36daff9489 100644
--- a/src/daemon/rpmostreed-transaction-types.c
+++ b/src/daemon/rpmostreed-transaction-types.c
@@ -2060,6 +2060,155 @@ rpmostreed_transaction_new_refresh_md (GDBusMethodInvocation *invocation,
 
 }
 
+/* ================================ ModifyYumRepo ================================ */
+
+typedef struct {
+  RpmostreedTransaction parent;
+  char *osname;
+  char *repo_id;
+  GVariant *settings;
+} ModifyYumRepoTransaction;
+
+typedef RpmostreedTransactionClass ModifyYumRepoTransactionClass;
+
+GType modify_yum_repo_transaction_get_type (void);
+
+G_DEFINE_TYPE (ModifyYumRepoTransaction,
+               modify_yum_repo_transaction,
+               RPMOSTREED_TYPE_TRANSACTION)
+
+static void
+modify_yum_repo_transaction_finalize (GObject *object)
+{
+  ModifyYumRepoTransaction *self;
+
+  self = (ModifyYumRepoTransaction *) object;
+  g_free (self->osname);
+  g_free (self->repo_id);
+  g_variant_unref (self->settings);
+
+  G_OBJECT_CLASS (modify_yum_repo_transaction_parent_class)->finalize (object);
+}
+
+static DnfRepo *
+get_dnf_repo_by_id (RpmOstreeContext *ctx, const char *repo_id)
+{
+  DnfContext *dnfctx = rpmostree_context_get_dnf (ctx);
+
+  GPtrArray *repos = dnf_context_get_repos (dnfctx);
+  for (guint i = 0; i < repos->len; i++)
+    {
+      DnfRepo *repo = repos->pdata[i];
+      if (g_strcmp0 (dnf_repo_get_id (repo), repo_id) == 0)
+        return repo;
+    }
+
+  return NULL;
+}
+
+static gboolean
+modify_yum_repo_transaction_execute (RpmostreedTransaction *transaction,
+                                     GCancellable *cancellable,
+                                     GError **error)
+{
+  ModifyYumRepoTransaction *self = (ModifyYumRepoTransaction *) transaction;
+  OstreeSysroot *sysroot = rpmostreed_transaction_get_sysroot (transaction);
+
+  rpmostree_transaction_set_title ((RPMOSTreeTransaction*)self, "modify-yum-repo");
+
+  g_autoptr(OstreeDeployment) cfg_merge_deployment =
+    ostree_sysroot_get_merge_deployment (sysroot, self->osname);
+
+  OstreeRepo *ot_repo = ostree_sysroot_repo (sysroot);
+  g_autoptr(RpmOstreeContext) ctx = rpmostree_context_new_system (ot_repo, cancellable, error);
+
+  /* We could bypass rpmostree_context_setup() here and call dnf_context_setup() ourselves
+   * since we're not actually going to perform any installation. Though it does provide us
+   * with the right semantics for install/source_root. */
+  if (!rpmostree_context_setup (ctx, NULL, NULL, NULL, cancellable, error))
+    return FALSE;
+
+  /* point libdnf to our repos dir */
+  rpmostree_context_configure_from_deployment (ctx, sysroot, cfg_merge_deployment);
+
+  DnfRepo *repo = get_dnf_repo_by_id (ctx, self->repo_id);
+  if (repo == NULL)
+    return glnx_throw (error, "Yum repo '%s' not found", self->repo_id);
+
+  GVariantIter iter;
+  GVariant *child;
+  g_variant_iter_init (&iter, self->settings);
+  while ((child = g_variant_iter_next_value (&iter)) != NULL)
+    {
+      const char *parameter = NULL;
+      const char *value = NULL;
+      g_variant_get_child (child, 0, "&s", &parameter);
+      g_variant_get_child (child, 1, "&s", &value);
+
+      /* Only allow changing 'enabled' for now. See the discussion about changing arbitrary
+       * .repo settings in https://github.com/projectatomic/rpm-ostree/pull/1780 */
+      if (g_strcmp0 (parameter, "enabled") != 0)
+        return glnx_throw (error, "Changing '%s' not allowed in yum .repo files", parameter);
+
+      if (g_strcmp0 (value, "0") != 0 &&
+          g_strcmp0 (value, "1") != 0)
+        return glnx_throw (error, "Only '0' and '1' are allowed for the '%s' key", parameter);
+
+      if (!dnf_repo_set_data (repo, parameter, value, error))
+        return FALSE;
+    }
+
+  if (!dnf_repo_commit (repo, error))
+    return FALSE;
+
+  return TRUE;
+}
+
+static void
+modify_yum_repo_transaction_class_init (CleanupTransactionClass *class)
+{
+  GObjectClass *object_class;
+
+  object_class = G_OBJECT_CLASS (class);
+  object_class->finalize = modify_yum_repo_transaction_finalize;
+
+  class->execute = modify_yum_repo_transaction_execute;
+}
+
+static void
+modify_yum_repo_transaction_init (ModifyYumRepoTransaction *self)
+{
+}
+
+RpmostreedTransaction *
+rpmostreed_transaction_new_modify_yum_repo (GDBusMethodInvocation *invocation,
+                                            OstreeSysroot         *sysroot,
+                                            const char            *osname,
+                                            const char            *repo_id,
+                                            GVariant              *settings,
+                                            GCancellable          *cancellable,
+                                            GError               **error)
+{
+  g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
+  g_return_val_if_fail (OSTREE_IS_SYSROOT (sysroot), NULL);
+
+  ModifyYumRepoTransaction *self =
+    g_initable_new (modify_yum_repo_transaction_get_type (),
+                    cancellable, error,
+                    "invocation", invocation,
+                    "sysroot-path", gs_file_get_path_cached (ostree_sysroot_get_path (sysroot)),
+                    NULL);
+
+  if (self != NULL)
+    {
+      self->osname = g_strdup (osname);
+      self->repo_id = g_strdup (repo_id);
+      self->settings = g_variant_ref (settings);
+    }
+
+  return (RpmostreedTransaction *) self;
+}
+
 /* ================================KernelArg================================ */
 
 typedef struct {
diff --git a/src/daemon/rpmostreed-transaction-types.h b/src/daemon/rpmostreed-transaction-types.h
index 837bb1b82a..ca40c11ca5 100644
--- a/src/daemon/rpmostreed-transaction-types.h
+++ b/src/daemon/rpmostreed-transaction-types.h
@@ -117,6 +117,16 @@ rpmostreed_transaction_new_refresh_md (GDBusMethodInvocation *invocation,
                                        const char            *osname,
                                        GCancellable          *cancellable,
                                        GError               **error);
+
+RpmostreedTransaction *
+rpmostreed_transaction_new_modify_yum_repo (GDBusMethodInvocation *invocation,
+                                            OstreeSysroot         *sysroot,
+                                            const char            *osname,
+                                            const char            *repo_id,
+                                            GVariant              *settings,
+                                            GCancellable          *cancellable,
+                                            GError               **error);
+
 typedef enum {
   RPMOSTREE_TRANSACTION_KERNEL_ARG_FLAG_REBOOT = (1 << 0),
 } RpmOstreeTransactionKernelArgFlags;