diff --git a/CHANGELOG.md b/CHANGELOG.md
index 20871780230bf339e39c97b0dd9424ef79e6bfb7..09336a86215f9216c5ba32ba74d81e47bf095f27 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,28 @@
 # Changelog
 
+## 2.5.1
+This release fixes a performance issue on session creation affecting large
+installations.
+
+Bug fixes:
+* Session import works again.
+
+Additional changes:
+* Libraries have been upgraded to fix potential bugs
+
+## 2.4.3
+This release fixes a performance issue on session creation affecting large
+installations.
+
+Bug fixes:
+* WebSocket communication now works correctly for course sessions.
+  (only affects installations using the LMS connector)
+* The configuration parameter `security.facebook.allowed-roles` is now
+  respected.
+
+Additional changes:
+* Libraries have been upgraded to fix potential bugs
+
 ## 2.5
 Major features:
 * Administration API: New endpoints have been added which are accessible by
diff --git a/src/main/java/de/thm/arsnova/dao/CouchDBDao.java b/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
index ecbdbcd15784c959ba6687eaf22a2a1f0dcb8df1..3265fb1ef8b169eda668297a5970bbe6f6c49ed8 100644
--- a/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
+++ b/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
@@ -533,9 +533,9 @@ public class CouchDBDao implements IDatabaseDao, ApplicationEventPublisherAware
 	}
 
 	@Override
-	@Transactional(isolation = Isolation.READ_COMMITTED)
 	public boolean sessionKeyAvailable(final String keyword) {
 		final View view = new View("session/by_keyword");
+		view.setKey(keyword);
 		final ViewResults results = getDatabase().view(view);
 
 		return !results.containsKey(keyword);