diff --git a/static/js/settings_bots.js b/static/js/settings_bots.js
index e3591b2ffa..9921c0d32f 100644
--- a/static/js/settings_bots.js
+++ b/static/js/settings_bots.js
@@ -324,10 +324,10 @@ exports.set_up = function () {
     });
 
     $("#inactive_bots_list").on("click", "button.reactivate_bot", function (e) {
-        var email = $(e.currentTarget).data('email');
+        var user_id = $(e.currentTarget).attr('data-user-id');
 
         channel.post({
-            url: '/json/users/' + encodeURIComponent(email) + "/reactivate",
+            url: '/json/users/' + encodeURIComponent(user_id) + "/reactivate",
             error: function (xhr) {
                 $('#bot_delete_error').text(JSON.parse(xhr.responseText).msg).show();
             },
diff --git a/static/js/settings_users.js b/static/js/settings_users.js
index 0f03388c43..79c72131d5 100644
--- a/static/js/settings_users.js
+++ b/static/js/settings_users.js
@@ -300,10 +300,10 @@ exports.on_load_success = function (realm_people_data) {
 
         // Go up the tree until we find the user row, then grab the email element
         var row = $(e.target).closest(".user_row");
-        var email = get_email_for_user_row(row);
+        var user_id = row.attr("data-user-id");
 
         channel.post({
-            url: '/json/users/' + encodeURIComponent(email) + "/reactivate",
+            url: '/json/users/' + encodeURIComponent(user_id) + "/reactivate",
             error: function (xhr) {
                 ui_report.generic_row_button_error(xhr, $(e.target));
             },
diff --git a/zerver/tests/test_users.py b/zerver/tests/test_users.py
index 96acc16d4e..013502d9ca 100644
--- a/zerver/tests/test_users.py
+++ b/zerver/tests/test_users.py
@@ -350,7 +350,7 @@ class ActivateTest(ZulipTestCase):
         user = self.example_user('hamlet')
         self.assertFalse(user.is_active)
 
-        result = self.client_post('/json/users/hamlet@zulip.com/reactivate')
+        result = self.client_post('/json/users/{}/reactivate'.format(user.id))
         self.assert_json_success(result)
         user = self.example_user('hamlet')
         self.assertTrue(user.is_active)
@@ -379,7 +379,8 @@ class ActivateTest(ZulipTestCase):
         self.assert_json_error(result, 'Cannot deactivate the only organization administrator')
 
         # Cannot reactivate a nonexistent user.
-        result = self.client_post('/json/users/nonexistent@zulip.com/reactivate')
+        invalid_user_id = 1000
+        result = self.client_post('/json/users/{}/reactivate'.format(invalid_user_id))
         self.assert_json_error(result, 'No such user')
 
     def test_api_with_insufficient_permissions(self) -> None:
@@ -392,7 +393,7 @@ class ActivateTest(ZulipTestCase):
         self.assert_json_error(result, 'Insufficient permission')
 
         # Cannot reactivate a user
-        result = self.client_post('/json/users/hamlet@zulip.com/reactivate')
+        result = self.client_post('/json/users/{}/reactivate'.format(self.example_user("hamlet").id))
         self.assert_json_error(result, 'Insufficient permission')
 
     def test_clear_scheduled_jobs(self) -> None:
diff --git a/zerver/views/users.py b/zerver/views/users.py
index 2a04384f82..f1d740bf54 100644
--- a/zerver/views/users.py
+++ b/zerver/views/users.py
@@ -79,9 +79,9 @@ def _deactivate_user_profile_backend(request: HttpRequest, user_profile: UserPro
     return json_success()
 
 def reactivate_user_backend(request: HttpRequest, user_profile: UserProfile,
-                            email: str) -> HttpResponse:
+                            user_id: int) -> HttpResponse:
     try:
-        target = get_user(email, user_profile.realm)
+        target = get_user_profile_by_id_in_realm(user_id, user_profile.realm)
     except UserProfile.DoesNotExist:
         return json_error(_('No such user'))
 
diff --git a/zproject/urls.py b/zproject/urls.py
index c8b81ad621..cf311b3f4a 100644
--- a/zproject/urls.py
+++ b/zproject/urls.py
@@ -126,7 +126,7 @@ v1_api_and_json_patterns = [
     url(r'^users$', rest_dispatch,
         {'GET': 'zerver.views.users.get_members_backend',
          'POST': 'zerver.views.users.create_user_backend'}),
-    url(r'^users/(?!me/)(?P<email>[^/]*)/reactivate$', rest_dispatch,
+    url(r'^users/(?P<user_id>[0-9]+)/reactivate$', rest_dispatch,
         {'POST': 'zerver.views.users.reactivate_user_backend'}),
     url(r'^users/(?!me/)(?P<email>[^/]*)/presence$', rest_dispatch,
         {'GET': 'zerver.views.presence.get_presence_backend'}),