diff --git a/indra/newview/llvoiceclient.cpp b/indra/newview/llvoiceclient.cpp
index e1dca4ae43527c0cd808471e5f60bf0d00e3ce1b..5c107cc10bd2a6833cb1888e1f8cc58973d12202 100644
--- a/indra/newview/llvoiceclient.cpp
+++ b/indra/newview/llvoiceclient.cpp
@@ -839,7 +839,7 @@ void LLVoiceClient::addObserver(LLVoiceClientStatusObserver* observer)
 
 void LLVoiceClient::removeObserver(LLVoiceClientStatusObserver* observer)
 {
-	if (mVoiceModule) mVoiceModule->removeObserver(observer);
+	if (mVoiceModule && mVoiceModule->singletoneInstanceExists()) mVoiceModule->removeObserver(observer);
 }
 
 void LLVoiceClient::addObserver(LLFriendObserver* observer)
@@ -849,7 +849,7 @@ void LLVoiceClient::addObserver(LLFriendObserver* observer)
 
 void LLVoiceClient::removeObserver(LLFriendObserver* observer)
 {
-	if (mVoiceModule) mVoiceModule->removeObserver(observer);
+	if (mVoiceModule && mVoiceModule->singletoneInstanceExists()) mVoiceModule->removeObserver(observer);
 }
 
 void LLVoiceClient::addObserver(LLVoiceClientParticipantObserver* observer)
@@ -859,7 +859,7 @@ void LLVoiceClient::addObserver(LLVoiceClientParticipantObserver* observer)
 
 void LLVoiceClient::removeObserver(LLVoiceClientParticipantObserver* observer)
 {
-	if (mVoiceModule) mVoiceModule->removeObserver(observer);
+	if (mVoiceModule && mVoiceModule->singletoneInstanceExists()) mVoiceModule->removeObserver(observer);
 }
 
 std::string LLVoiceClient::sipURIFromID(const LLUUID &id)
diff --git a/indra/newview/llvoiceclient.h b/indra/newview/llvoiceclient.h
index 337f01f3e53573639673603609f17cc419014a48..758e9cecd76acd69cdafc782cca61bfd85096430 100644
--- a/indra/newview/llvoiceclient.h
+++ b/indra/newview/llvoiceclient.h
@@ -121,6 +121,8 @@ public:
 
 	virtual const LLVoiceVersionInfo& getVersion()=0;
 	
+	virtual bool singletoneInstanceExists()=0;
+	
 	/////////////////////
 	/// @name Tuning
 	//@{
diff --git a/indra/newview/llvoicevivox.cpp b/indra/newview/llvoicevivox.cpp
index b039afa73418b118a8fed76aa87afc7c1e283df1..ee333bcee2815d2d3d8f871eadbb1c963eb944af 100644
--- a/indra/newview/llvoicevivox.cpp
+++ b/indra/newview/llvoicevivox.cpp
@@ -4726,6 +4726,11 @@ void LLVivoxVoiceClient::declineInvite(std::string &sessionHandle)
 	}
 }
 
+bool LLVivoxVoiceClient::singletoneInstanceExists()
+{
+	return LLVivoxVoiceClient::instanceExists();
+}
+
 void LLVivoxVoiceClient::leaveNonSpatialChannel()
 {
     LL_DEBUGS("Voice") << "Request to leave spacial channel." << LL_ENDL;
diff --git a/indra/newview/llvoicevivox.h b/indra/newview/llvoicevivox.h
index 50862cea1ee941f9d2b51d1e7ceba397ff473e1f..210c7264527fe8f591e007c6eb8c411221f8bfd1 100644
--- a/indra/newview/llvoicevivox.h
+++ b/indra/newview/llvoicevivox.h
@@ -73,6 +73,8 @@ public:
 
 	// Returns true if vivox has successfully logged in and is not in error state	
 	virtual bool isVoiceWorking() const;
+	
+	virtual bool singletoneInstanceExists();
 
 	/////////////////////
 	/// @name Tuning