diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
index 09722e7c28..965c1f04f1 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
@@ -2325,11 +2325,12 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                         appearance = new AvatarAppearance();
                         appearance.Unpack(appearanceOsd);
                     }
+                    else
+                    {
+                        OSSLError(string.Format("osNpcCreate: Notecard reference '{0}' not found.", notecard));
+                    }
                 }
 
-                if (appearance == null)
-                    return new LSL_Key(UUID.Zero.ToString());
-
                 UUID ownerID = UUID.Zero;
                 if (owned)
                     ownerID = m_host.OwnerID;
@@ -2394,8 +2395,8 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                 string appearanceSerialized = LoadNotecard(notecard);
 
                 if (appearanceSerialized == null)
-                    return;
-                
+                    OSSLError(string.Format("osNpcCreate: Notecard reference '{0}' not found.", notecard));
+
                 OSDMap appearanceOsd = (OSDMap)OSDParser.DeserializeLLSDXml(appearanceSerialized);
 //                OSD a = OSDParser.DeserializeLLSDXml(appearanceSerialized);
 //                Console.WriteLine("appearanceSerialized {0}", appearanceSerialized);
diff --git a/OpenSim/Region/ScriptEngine/Shared/Tests/OSSL_ApiNpcTests.cs b/OpenSim/Region/ScriptEngine/Shared/Tests/OSSL_ApiNpcTests.cs
index 4e58315ee5..b49bcc2000 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Tests/OSSL_ApiNpcTests.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Tests/OSSL_ApiNpcTests.cs
@@ -127,11 +127,19 @@ namespace OpenSim.Region.ScriptEngine.Shared.Tests
             OSSL_Api osslApi = new OSSL_Api();
             osslApi.Initialize(m_engine, so.RootPart, null);
 
-            string npcRaw
-                = osslApi.osNpcCreate("Jane", "Doe", new LSL_Types.Vector3(128, 128, 128), "not existing notecard name");
+            string npcRaw;
+            bool gotExpectedException = false;
+            try
+            {
+                npcRaw
+                    = osslApi.osNpcCreate("Jane", "Doe", new LSL_Types.Vector3(128, 128, 128), "not existing notecard name");
+            }
+            catch (ScriptException)
+            {
+                gotExpectedException = true;
+            }
 
-            UUID npcId = new UUID(npcRaw);
-            Assert.That(npcId, Is.EqualTo(UUID.Zero));
+            Assert.That(gotExpectedException, Is.True);
         }
 
         /// <summary>
@@ -233,7 +241,17 @@ namespace OpenSim.Region.ScriptEngine.Shared.Tests
             string npcRaw
                 = osslApi.osNpcCreate("Jane", "Doe", new LSL_Types.Vector3(128, 128, 128), firstAppearanceNcName);
 
-            osslApi.osNpcLoadAppearance(npcRaw, secondAppearanceNcName);
+            bool gotExpectedException = false;
+            try
+            {
+                osslApi.osNpcLoadAppearance(npcRaw, secondAppearanceNcName);
+            }
+            catch (ScriptException)
+            {
+                gotExpectedException = true;
+            }
+
+            Assert.That(gotExpectedException, Is.True);
 
             UUID npcId = new UUID(npcRaw);
             ScenePresence npc = m_scene.GetScenePresence(npcId);