diff --git a/OpenSim/Region/CoreModules/Avatar/InstantMessage/MessageTransferModule.cs b/OpenSim/Region/CoreModules/Avatar/InstantMessage/MessageTransferModule.cs
index 1406aaec25..0c067d7c61 100644
--- a/OpenSim/Region/CoreModules/Avatar/InstantMessage/MessageTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Avatar/InstantMessage/MessageTransferModule.cs
@@ -137,6 +137,9 @@ namespace OpenSim.Region.CoreModules.Avatar.InstantMessage
         {
             UUID toAgentID = new UUID(im.toAgentID);
 
+            if (toAgentID == UUID.Zero)
+                return;
+
             // Try root avatar only first
             foreach (Scene scene in m_Scenes)
             {
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs
index d5e611c5e4..f9b4bfd475 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs
@@ -3420,7 +3420,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
         public void llInstantMessage(string user, string message)
         {
             UUID result;
-            if (!UUID.TryParse(user, out result))
+            if (!UUID.TryParse(user, out result) || result == UUID.Zero)
             {
                 ShoutError("An invalid key  was passed to llInstantMessage");
                 ScriptSleep(2000);