diff --git a/src/game/ObjectMgr.cpp b/src/game/ObjectMgr.cpp
index 38fc56cd4..4c0bcd345 100644
--- a/src/game/ObjectMgr.cpp
+++ b/src/game/ObjectMgr.cpp
@@ -677,7 +677,8 @@ void ObjectMgr::LoadCreatureTemplates()
             }
         }
 
-        if (cInfo->unit_class && ((1 << (cInfo->unit_class-1)) & CLASSMASK_ALL_CREATURES) == 0)
+        // use below code for 0-checks for unit_class
+        if (/*!cInfo->unit_class ||*/cInfo->unit_class && ((1 << (cInfo->unit_class-1)) & CLASSMASK_ALL_CREATURES) == 0)
             sLog.outErrorDb("Creature (Entry: %u) has invalid unit_class(%u) for creature_template", cInfo->Entry, cInfo->unit_class);
 
         if(cInfo->dmgschool >= MAX_SPELL_SCHOOL)
diff --git a/src/game/SharedDefines.h b/src/game/SharedDefines.h
index db3183480..7004a18ac 100644
--- a/src/game/SharedDefines.h
+++ b/src/game/SharedDefines.h
@@ -89,7 +89,16 @@ enum Classes
     (1<<(CLASS_MAGE-1))   |(1<<(CLASS_WARLOCK-1))|(1<<(CLASS_DRUID-1)) | \
     (1<<(CLASS_DEATH_KNIGHT-1)) )
 
-#define CLASSMASK_ALL_CREATURES ((1<<(CLASS_WARRIOR-1)) | (1<<(CLASS_PALADIN-1)) | (1<<(CLASS_ROGUE-1)) | (1<<(CLASS_MAGE-1)) )
+// valid classes for creature_template.unit_class
+enum UnitClass
+{
+    UNIT_CLASS_WARRIOR                  = 1,
+    UNIT_CLASS_PALADIN                  = 2,
+    UNIT_CLASS_ROGUE                    = 4,
+    UNIT_CLASS_MAGE                     = 8,
+};
+
+#define CLASSMASK_ALL_CREATURES ((1<<(UNIT_CLASS_WARRIOR-1)) | (1<<(UNIT_CLASS_PALADIN-1)) | (1<<(UNIT_CLASS_ROGUE-1)) | (1<<(UNIT_CLASS_MAGE-1)) )
 
 #define CLASSMASK_WAND_USERS ((1<<(CLASS_PRIEST-1))|(1<<(CLASS_MAGE-1))|(1<<(CLASS_WARLOCK-1)))
 
diff --git a/src/shared/revision_nr.h b/src/shared/revision_nr.h
index 0f8ab1ec0..e4a28282e 100644
--- a/src/shared/revision_nr.h
+++ b/src/shared/revision_nr.h
@@ -1,4 +1,4 @@
 #ifndef __REVISION_NR_H__
 #define __REVISION_NR_H__
- #define REVISION_NR "9175"
+ #define REVISION_NR "9176"
 #endif // __REVISION_NR_H__