diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 08d54b68..1d177b32 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -5,6 +5,16 @@ Changelog for the **SODAR Core** Django app package. Loosely follows the
 `Keep a Changelog <http://keepachangelog.com/en/1.0.0/>`_ guidelines.
 
 
+Unreleased
+==========
+
+Fixed
+-----
+
+- **Projectroles**
+    - Browser-specific ``sodar-btn-submit-once`` spinner padding (#1291)
+
+
 v0.13.2 (2023-09-21)
 ====================
 
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 1664d52d..e096c957 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -29,7 +29,7 @@
 # The short X.Y version
 version = '0.13'
 # The full version, including alpha/beta/rc tags
-release = '0.13.2'
+release = '0.13.3-WIP'
 
 
 # -- General configuration ---------------------------------------------------
diff --git a/docs/source/major_changes.rst b/docs/source/major_changes.rst
index 1f0aeb8d..79ab8248 100644
--- a/docs/source/major_changes.rst
+++ b/docs/source/major_changes.rst
@@ -10,6 +10,12 @@ older SODAR Core version. For a complete list of changes in current and previous
 releases, see the :ref:`full changelog<changelog>`.
 
 
+v0.13.3 (WIP)
+*************
+
+TBA
+
+
 v0.13.2 (2023-09-21)
 ********************
 
diff --git a/projectroles/static/projectroles/css/projectroles.css b/projectroles/static/projectroles/css/projectroles.css
index 1b71b815..7ba00062 100644
--- a/projectroles/static/projectroles/css/projectroles.css
+++ b/projectroles/static/projectroles/css/projectroles.css
@@ -593,6 +593,16 @@ span.select2-selection__rendered {
   color: #495057 !important;
 }
 
+/* Fix browser-specific submit button spinner alignment (#1291) */
+.sodar-btn-spinner {
+    margin-bottom: 1px;
+  }
+@supports (-moz-appearance:none) {
+  .sodar-btn-spinner {
+    margin-bottom: 2px;
+  }
+}
+
 
 /* Text --------------------------------------------------------------------- */
 
diff --git a/projectroles/static/projectroles/js/projectroles.js b/projectroles/static/projectroles/js/projectroles.js
index 7b40f7ed..640eded9 100644
--- a/projectroles/static/projectroles/js/projectroles.js
+++ b/projectroles/static/projectroles/js/projectroles.js
@@ -326,7 +326,8 @@ $(document).ready(function () {
     $('.sodar-btn-submit-once').click(function () {
         $(this).attr('disabled', true);
         $(this).find('svg').remove();
-        $(this).prepend('<span class="spinner-border spinner-border-sm" ' +
+        $(this).prepend(
+            '<span class="spinner-border spinner-border-sm sodar-btn-spinner" ' +
             'role="status" aria-hidden="true"></span>');
         $("body").css("cursor", "progress");
         $(this).closest('form').submit();