diff --git a/README.md b/README.md
index 7721f28..6ed9510 100644
--- a/README.md
+++ b/README.md
@@ -93,7 +93,7 @@ All character types are stored in ASCII where the smallest byte corresponds to t
 | `0...3` | *signature*<br>`PODX` |
 | `4...7` | *endianness*<br>`LITE` little endian<br>`BIGE` big endian |
 | `8...11` | *checksum*<br>`NONE` no checksum<br>`AD32` adler32 <br>`CR32` crc32 |
-| `12...15` | *reserved* |
+| `12...15` | *reserved*<br>`NONE` |
 
 #### BODY
 | byte(s) | value(s)
diff --git a/src/PxLoadFile.cpp b/src/PxLoadFile.cpp
index 7e91c65..f60c040 100644
--- a/src/PxLoadFile.cpp
+++ b/src/PxLoadFile.cpp
@@ -299,6 +299,13 @@ PxResult pxLoadFile(PxContainer* container, const char* fileName, PxChecksum che
     {
         return PS_FILE_CORRUPT;
     }
+    
+    // Reserved
+    if (memcmp(header + 12, cNONE, 4) != 0)
+    {
+        return PS_FILE_CORRUPT;
+    }
+
 
     // Calculate checksum
 
diff --git a/src/PxSaveFile.cpp b/src/PxSaveFile.cpp
index 1baf679..f7cca4e 100644
--- a/src/PxSaveFile.cpp
+++ b/src/PxSaveFile.cpp
@@ -177,8 +177,8 @@ PxResult pxSaveFile(PxContainer* container, const char* fileName, PxCompression
             return PS_ARGUMENT_ERROR;
     }
 
-    // Padding
-    memset(header + 12, 0, 4);
+    // Reserved Bytes
+    memcpy(header + 12, cNONE, 4);
 
     file.write(header, 16);