diff --git a/CommonHelpers/InpOut.cs b/CommonHelpers/InpOut.cs
index d9a3a2b..80dc6d4 100644
--- a/CommonHelpers/InpOut.cs
+++ b/CommonHelpers/InpOut.cs
@@ -20,6 +20,8 @@ namespace CommonHelpers
         public InpOut()
         {
             libraryHandle = LoadLibrary(LibraryName);
+            if (libraryHandle == IntPtr.Zero)
+                throw new ArgumentException("Failed to load " + LibraryName);
             try
             {
                 var addr = GetProcAddress(libraryHandle, "MapPhysToLin");