diff --git a/src/game/ObjectGuid.h b/src/game/ObjectGuid.h
index b3c06ca80..c76ddce1c 100644
--- a/src/game/ObjectGuid.h
+++ b/src/game/ObjectGuid.h
@@ -85,6 +85,8 @@ struct PackedGuidReader
     ObjectGuid* m_guidPtr;
 };
 
+#define NUM_GUID_BYTES sizeof(uint64)
+
 class MANGOS_DLL_SPEC ObjectGuid
 {
     public:                                                 // constructors
@@ -174,23 +176,23 @@ class MANGOS_DLL_SPEC ObjectGuid
 
         uint8& operator[] (uint8 index)
         {
-            MANGOS_ASSERT(index < 8);
+            MANGOS_ASSERT(index < NUM_GUID_BYTES);
 
 #if MANGOS_ENDIAN == MANGOS_LITTLEENDIAN
             return m_guidBytes[index];
 #else
-            return m_guidBytes[7 - index];
+            return m_guidBytes[NUM_GUID_BYTES - 1 - index];
 #endif
         }
 
         uint8 const& operator[] (uint8 index) const
         {
-            MANGOS_ASSERT(index < 8);
+            MANGOS_ASSERT(index < NUM_GUID_BYTES);
 
 #if MANGOS_ENDIAN == MANGOS_LITTLEENDIAN
             return m_guidBytes[index];
 #else
-            return m_guidBytes[7 - index];
+            return m_guidBytes[NUM_GUID_BYTES - 1 - index];
 #endif
         }
 
@@ -228,7 +230,7 @@ class MANGOS_DLL_SPEC ObjectGuid
         union
         {
             uint64 m_guid;
-            uint8 m_guidBytes[8];
+            uint8 m_guidBytes[NUM_GUID_BYTES];
         };
 };