diff --git a/apps/telepathy/MyUserAgent.cxx b/apps/telepathy/MyUserAgent.cxx
index ab6e4ac66e..2933fd9c36 100644
--- a/apps/telepathy/MyUserAgent.cxx
+++ b/apps/telepathy/MyUserAgent.cxx
@@ -50,7 +50,7 @@ tr::MyUserAgent::onSubscriptionTerminated(SubscriptionHandle handle, unsigned in
 }
 
 void
-tr::MyUserAgent::onSubscriptionNotify(SubscriptionHandle handle, Data& notifyData)
+tr::MyUserAgent::onSubscriptionNotify(SubscriptionHandle handle, const Data& notifyData)
 {
    InfoLog(<< "onSubscriptionNotify: handle=" << handle << " data=" << endl << notifyData);
 }
diff --git a/apps/telepathy/MyUserAgent.hxx b/apps/telepathy/MyUserAgent.hxx
index 01072aac98..d6141dc59b 100644
--- a/apps/telepathy/MyUserAgent.hxx
+++ b/apps/telepathy/MyUserAgent.hxx
@@ -37,7 +37,7 @@ public:
    MyUserAgent(recon::ConversationManager* conversationManager, resip::SharedPtr<recon::UserAgentMasterProfile> profile, Connection& connection);
    virtual void onApplicationTimer(unsigned int id, unsigned int durationMs, unsigned int seq);
    virtual void onSubscriptionTerminated(recon::SubscriptionHandle handle, unsigned int statusCode);
-   virtual void onSubscriptionNotify(recon::SubscriptionHandle handle, resip::Data& notifyData);
+   virtual void onSubscriptionNotify(recon::SubscriptionHandle handle, const resip::Data& notifyData);
    virtual void onSuccess(resip::ClientRegistrationHandle h, const resip::SipMessage& response);
    virtual void onRemoved(resip::ClientRegistrationHandle, const resip::SipMessage& response);
    virtual void onFailure(resip::ClientRegistrationHandle, const resip::SipMessage& response);
diff --git a/resip/recon/MOHParkServer/Server.cxx b/resip/recon/MOHParkServer/Server.cxx
index a551c0fc1f..cd4edc7dbc 100644
--- a/resip/recon/MOHParkServer/Server.cxx
+++ b/resip/recon/MOHParkServer/Server.cxx
@@ -80,7 +80,7 @@ class MyUserAgent : public UserAgent
       InfoLog(<< "onSubscriptionTerminated: handle=" << handle << " statusCode=" << statusCode);
    }
 
-   virtual void onSubscriptionNotify(SubscriptionHandle handle, Data& notifyData)
+   virtual void onSubscriptionNotify(SubscriptionHandle handle, const Data& notifyData)
    {
       InfoLog(<< "onSubscriptionNotify: handle=" << handle << " data=" << endl << notifyData);
    }
diff --git a/resip/recon/test/testUA.cxx b/resip/recon/test/testUA.cxx
index 93b9e5bc35..27f09829d2 100644
--- a/resip/recon/test/testUA.cxx
+++ b/resip/recon/test/testUA.cxx
@@ -88,7 +88,7 @@ class MyUserAgent : public UserAgent
       InfoLog(<< "onSubscriptionTerminated: handle=" << handle << " statusCode=" << statusCode);
    }
 
-   virtual void onSubscriptionNotify(SubscriptionHandle handle, Data& notifyData)
+   virtual void onSubscriptionNotify(SubscriptionHandle handle, const Data& notifyData)
    {
       InfoLog(<< "onSubscriptionNotify: handle=" << handle << " data=" << endl << notifyData);
    }
diff --git a/resip/recon/test/unitTests.cxx b/resip/recon/test/unitTests.cxx
index bf092802fa..86d378069a 100644
--- a/resip/recon/test/unitTests.cxx
+++ b/resip/recon/test/unitTests.cxx
@@ -615,7 +615,7 @@ class MyUserAgent : public UserAgent
       InfoLog(<< "onSubscriptionTerminated: handle=" << handle << " statusCode=" << statusCode);
    }
 
-   virtual void onSubscriptionNotify(SubscriptionHandle handle, Data& notifyData)
+   virtual void onSubscriptionNotify(SubscriptionHandle handle, const Data& notifyData)
    {
       InfoLog(<< "onSubscriptionNotify: handle=" << handle << " data=" << endl << notifyData);
    }