diff --git a/include/game/packet_parsers.hpp b/include/game/packet_parsers.hpp
index 9fb0f166..40655045 100644
--- a/include/game/packet_parsers.hpp
+++ b/include/game/packet_parsers.hpp
@@ -419,6 +419,10 @@ public:
     bool parseMonsterMove(network::Packet& packet, MonsterMoveData& data) override {
         return MonsterMoveParser::parseVanilla(packet, data);
     }
+    // Classic 1.12 SMSG_INITIAL_SPELLS: uint16 spellId + uint16 slot per entry (not uint32 + uint16)
+    bool parseInitialSpells(network::Packet& packet, InitialSpellsData& data) override {
+        return InitialSpellsParser::parse(packet, data, /*vanillaFormat=*/true);
+    }
     // Classic 1.12 uses PackedGuid (not full uint64) and uint16 castFlags (not uint32)
     bool parseSpellStart(network::Packet& packet, SpellStartData& data) override;
     bool parseSpellGo(network::Packet& packet, SpellGoData& data) override;
diff --git a/include/game/world_packets.hpp b/include/game/world_packets.hpp
index 539d3b8a..6e5721fd 100644
--- a/include/game/world_packets.hpp
+++ b/include/game/world_packets.hpp
@@ -1758,7 +1758,10 @@ struct InitialSpellsData {
 
 class InitialSpellsParser {
 public:
-    static bool parse(network::Packet& packet, InitialSpellsData& data);
+    // vanillaFormat=true: Classic 1.12 uint16 spellId + uint16 slot (4 bytes/spell)
+    // vanillaFormat=false: TBC/WotLK uint32 spellId + uint16 unk (6 bytes/spell)
+    static bool parse(network::Packet& packet, InitialSpellsData& data,
+                      bool vanillaFormat = false);
 };
 
 /** CMSG_CAST_SPELL packet builder */
diff --git a/src/game/world_packets.cpp b/src/game/world_packets.cpp
index 8c7c5ec9..b7d8075b 100644
--- a/src/game/world_packets.cpp
+++ b/src/game/world_packets.cpp
@@ -2901,18 +2901,13 @@ bool XpGainParser::parse(network::Packet& packet, XpGainData& data) {
 // Phase 3: Spells, Action Bar, Auras
 // ============================================================
 
-bool InitialSpellsParser::parse(network::Packet& packet, InitialSpellsData& data) {
-    size_t packetSize = packet.getSize();
+bool InitialSpellsParser::parse(network::Packet& packet, InitialSpellsData& data,
+                                bool vanillaFormat) {
     data.talentSpec = packet.readUInt8();
     uint16_t spellCount = packet.readUInt16();
 
-    // Detect vanilla (uint16 spellId) vs WotLK (uint32 spellId) format
-    // Vanilla: 4 bytes/spell (uint16 id + uint16 slot), WotLK: 6 bytes/spell (uint32 id + uint16 unk)
-    size_t remainingAfterHeader = packetSize - 3; // subtract talentSpec(1) + spellCount(2)
-    bool vanillaFormat = remainingAfterHeader < static_cast<size_t>(spellCount) * 6 + 2;
-
-    LOG_DEBUG("SMSG_INITIAL_SPELLS: packetSize=", packetSize, " bytes, spellCount=", spellCount,
-              vanillaFormat ? " (vanilla uint16 format)" : " (WotLK uint32 format)");
+    LOG_DEBUG("SMSG_INITIAL_SPELLS: spellCount=", spellCount,
+              vanillaFormat ? " (vanilla uint16 format)" : " (TBC/WotLK uint32 format)");
 
     data.spellIds.reserve(spellCount);
     for (uint16_t i = 0; i < spellCount; ++i) {