diff --git a/resources/assets/javascripts/bootstrap/sidebar.js b/resources/assets/javascripts/bootstrap/sidebar.js
index df21f16acf704831aa89629c802872a28fd99eb4..5e89a7fc472e03537df7709609ad8c47e407ed51 100644
--- a/resources/assets/javascripts/bootstrap/sidebar.js
+++ b/resources/assets/javascripts/bootstrap/sidebar.js
@@ -3,6 +3,7 @@ import eventBus from '../lib/event-bus.ts';
 STUDIP.ready(() => {
     // Manually nudge sidebar under main header.
     STUDIP.Sidebar.place();
+
     STUDIP.Sidebar.observeBody();
     STUDIP.Sidebar.observeFooter();
     STUDIP.Sidebar.observeSidebar();
@@ -10,5 +11,4 @@ STUDIP.ready(() => {
     document.defaultView.addEventListener('resize',() => {
         STUDIP.Sidebar.reset();
     });
-
 });
diff --git a/resources/assets/javascripts/lib/sidebar.js b/resources/assets/javascripts/lib/sidebar.js
index 17c96b90a3bff64e7bd1e56ea5f6d4a5ee8d4e07..17362fa017c4eb400336ab018e1ff9cac82d40fc 100644
--- a/resources/assets/javascripts/lib/sidebar.js
+++ b/resources/assets/javascripts/lib/sidebar.js
@@ -22,7 +22,7 @@ const Sidebar = {
         const sidebar = document.getElementById('sidebar');
         if (sidebar) {
             const sObserver = new IntersectionObserver(STUDIP.Sidebar.fits, options);
-            sObserver.observe(sidebar, options);
+            sObserver.observe();
         }
     },
 
@@ -36,11 +36,11 @@ const Sidebar = {
             for (const mutation of mutations) {
                 if ((!mutation.oldValue || mutation.oldValue.indexOf('fixed') === -1)
                     && mutation.target.classList.contains('fixed')) {
-                    sidebar.style.top = '';
                     sidebar.classList.add('fixed');
+                    sidebar.style.top = '';
                 } else if (mutation.oldValue && mutation.oldValue.indexOf('fixed') !== -1
                     && !mutation.target.classList.contains('fixed')) {
-                    STUDIP.Sidebar.reset();
+                    sidebar.classList.remove('fixed');
                 }
             }
         });
@@ -64,18 +64,17 @@ const Sidebar = {
          * Observe if the footer is visible in viewport.
          */
         const fObserver = new IntersectionObserver(STUDIP.Sidebar.footerVisible, options);
-        fObserver.observe(document.getElementById('main-footer'), options);
+        fObserver.observe(document.getElementById('main-footer'));
 
     },
 
     reset() {
         const sidebar = document.getElementById('sidebar');
         if (sidebar) {
-            sidebar.classList.remove('oversized', 'was-oversized', 'fixed');
+            sidebar.classList.remove('oversized', 'adjusted', 'fixed');
             sidebar.style.top = '';
-            STUDIP.Sidebar.place();
-            STUDIP.Sidebar.observeSidebar();
         }
+        STUDIP.Sidebar.observe();
     },
 
     fits(entries, observer) {
@@ -86,7 +85,7 @@ const Sidebar = {
                 if (entry.isIntersecting) {
                     sidebar.classList.remove('oversized');
                 } else {
-                    sidebar.classList.add('oversized', 'was-oversized');
+                    sidebar.classList.add('oversized', 'adjusted');
                 }
             });
         }
@@ -98,9 +97,13 @@ const Sidebar = {
             entries.forEach(entry => {
                 // Footer is visible on current page.
                 if (entry.isIntersecting) {
-                    sidebar.classList.remove('no-footer');
+                    if (sidebar.classList.contains('no-footer')) {
+                        sidebar.classList.remove('no-footer');
+                    }
                 } else {
-                    sidebar.classList.add('no-footer');
+                    if (!sidebar.classList.contains('no-footer')) {
+                        sidebar.classList.add('no-footer');
+                    }
                 }
             });
         }
diff --git a/resources/assets/stylesheets/scss/sidebar.scss b/resources/assets/stylesheets/scss/sidebar.scss
index d03ede6057754e6610f8a529ac62b92d00eadea3..60114c7dbab95835f1e309f20e83f68896d1028f 100644
--- a/resources/assets/stylesheets/scss/sidebar.scss
+++ b/resources/assets/stylesheets/scss/sidebar.scss
@@ -1,7 +1,7 @@
 #sidebar {
+    background: $white;
     border-left: 0;
     display: inline-block;
-    height: max-content;
     margin-bottom: $page-margin + 35px;
     margin-top: 15px;
     padding: 0 5px 7px 15px;
@@ -11,11 +11,7 @@
     width: $sidebar-width;
     z-index: 2;
 
-    &.fixed {
-        top: 55px;
-    }
-
-    &.was-oversized {
+    &.adjusted {
         height: calc(100vh - 265px);
         position: fixed;
         overflow-x: hidden;