diff --git a/Editor/Extensions/MonoScriptExtensions.cs b/Editor/Extensions/MonoScriptExtensions.cs
index 4b33aac..a2ed598 100644
--- a/Editor/Extensions/MonoScriptExtensions.cs
+++ b/Editor/Extensions/MonoScriptExtensions.cs
@@ -89,9 +89,13 @@ private static string GetProperClassName(string rawClassName)
         /// </returns>
         [PublicAPI, NotNull] public static string GetAssemblyName(this MonoScript script)
         {
-            string assemblyName = script.Internal_GetAssemblyName();
+	    string assemblyName = script.Internal_GetAssemblyName();
             int lastDotIndex = assemblyName.LastIndexOf('.');
-            return lastDotIndex == -1 ? string.Empty : assemblyName.Substring(0, lastDotIndex);
+	    if(assemblyName == null || assemblyName == string.Empty)
+	    {
+		return string.Empty;
+	    }
+	    return lastDotIndex == -1 ? assemblyName : assemblyName.Substring(0, lastDotIndex);
         }
 
         private static string GetNamespaceName(this MonoScript asset)
@@ -101,4 +105,4 @@ private static string GetNamespaceName(this MonoScript asset)
             return match.Success ? match.Value : string.Empty;
         }
     }
-}
\ No newline at end of file
+}