diff --git a/README.md b/README.md
index e3d0185..f305b01 100644
--- a/README.md
+++ b/README.md
@@ -29,7 +29,7 @@ Usage info
 WhiteRabbit.exe < wordlist
 ```
 
-**Note that this code only works correctly on big-endian x64 systems, due to heavy optimizations of MD5 computation!**
+**Note that this code only works correctly on little-endian x64 systems, due to heavy optimizations of MD5 computation!**
 
 Performance
 ===========
diff --git a/WhiteRabbit/Program.cs b/WhiteRabbit/Program.cs
index 70e9ce9..0c34d8a 100644
--- a/WhiteRabbit/Program.cs
+++ b/WhiteRabbit/Program.cs
@@ -39,6 +39,11 @@
                 return;
             }
 
+            if (IntPtr.Size != 8)
+            {
+                Console.WriteLine("Only 64-bit systems are supported due to MD5Digest optimizations");
+            }
+
             var expectedHashesAsVectors = ConfigurationManager.AppSettings["ExpectedHashes"]
                 .Split(',')
                 .Select(hash => new Vector<uint>(HexadecimalStringToUnsignedIntArray(hash)))