diff --git a/indra/newview/llfloaterimcontainer.cpp b/indra/newview/llfloaterimcontainer.cpp
index a0c386717bee99644d12cdc75225b237a0862914..74490b695c6a2a6d250b82cd8a9d8729e9d0321d 100644
--- a/indra/newview/llfloaterimcontainer.cpp
+++ b/indra/newview/llfloaterimcontainer.cpp
@@ -114,6 +114,7 @@ void LLFloaterIMContainer::sessionAdded(const LLUUID& session_id, const std::str
 void LLFloaterIMContainer::sessionActivated(const LLUUID& session_id, const std::string& name, const LLUUID& other_participant_id)
 {
 	selectConversationPair(session_id, true);
+	collapseMessagesPane(false);
 }
 
 void LLFloaterIMContainer::sessionVoiceOrIMStarted(const LLUUID& session_id)