diff --git a/src/server/scripts/Spells/spell_item.cpp b/src/server/scripts/Spells/spell_item.cpp
index cbb9e10bc4..d2a546c698 100644
--- a/src/server/scripts/Spells/spell_item.cpp
+++ b/src/server/scripts/Spells/spell_item.cpp
@@ -5104,26 +5104,15 @@ class spell_item_blaze_of_life : public SpellScript
     }
 };
 
-enum ItemObsidianArmor
+static std::array<uint32 /*spellId*/, MAX_SPELL_SCHOOL - 1> const ResistanceSpellsBySchool =
 {
-    SPELL_FIRE_RESISTANCE       = 27533,
-    SPELL_ARCANCE_RESISTANCE    = 27540,
-    SPELL_NATURE_RESISTANCE     = 27538,
-    SPELL_HOLY_RESISTANCE       = 27536,
-    SPELL_SHADOW_RESISTANCE     = 27535,
-    SPELL_FROST_RESISTANCE      = 27534,
-
-};
-
-static std::array<uint32 /*spellId*/, MAX_SPELL_SCHOOL> const ResistanceSpellsBySchool =
-{
-    0,                          // SPELL_SCHOOL_NORMAL - no shield
-    SPELL_HOLY_RESISTANCE,      // SPELL_SCHOOL_HOLY
-    SPELL_FIRE_RESISTANCE,      // SPELL_SCHOOL_FIRE
-    SPELL_NATURE_RESISTANCE,    // SPELL_SCHOOL_NATURE
-    SPELL_FROST_RESISTANCE,     // SPELL_SCHOOL_FROST
-    SPELL_SHADOW_RESISTANCE,    // SPELL_SCHOOL_SHADOW
-    SPELL_ARCANCE_RESISTANCE    // SPELL_SCHOOL_ARCANE
+    // SPELL_SCHOOL_NORMAL has no shield
+    27536, // SPELL_SCHOOL_HOLY
+    27533, // SPELL_SCHOOL_FIRE
+    27538, // SPELL_SCHOOL_NATURE
+    27534, // SPELL_SCHOOL_FROST
+    27535, // SPELL_SCHOOL_SHADOW
+    27540  // SPELL_SCHOOL_ARCANE
 };
 
 // 27539 - Obsidian Armor
@@ -5131,15 +5120,7 @@ class spell_item_obsidian_armor : public AuraScript
 {
     bool Validate(SpellInfo const* /*spell*/) override
     {
-        return ValidateSpellInfo(
-            {
-                SPELL_HOLY_RESISTANCE,
-                SPELL_FIRE_RESISTANCE,
-                SPELL_NATURE_RESISTANCE,
-                SPELL_FROST_RESISTANCE,
-                SPELL_SHADOW_RESISTANCE,
-                SPELL_ARCANCE_RESISTANCE
-            });
+        return ValidateSpellInfo(ResistanceSpellsBySchool);
     }
 
     void HandleProc(AuraEffect const* aurEff, ProcEventInfo& eventInfo)
@@ -5150,7 +5131,7 @@ class spell_item_obsidian_armor : public AuraScript
         for (uint8 i = SPELL_SCHOOL_HOLY; i < MAX_SPELL_SCHOOL; ++i)
         {
             if ((eventInfo.GetSpellInfo()->GetSchoolMask() & (1 << i)) != 0)
-                GetTarget()->CastSpell(GetTarget(), ResistanceSpellsBySchool[i], aurEff);
+                GetTarget()->CastSpell(GetTarget(), ResistanceSpellsBySchool[i - 1], aurEff);
         }
     }