diff --git a/Source/msg.cpp b/Source/msg.cpp
index 1acf5a514..166731648 100644
--- a/Source/msg.cpp
+++ b/Source/msg.cpp
@@ -1036,6 +1036,10 @@ DWORD OnSpellWall(const TCmd *pCmd, Player &player)
 		return sizeof(message);
 
 	auto spell = static_cast<spell_id>(message.wParam1);
+	if (!IsValidSpell(spell)) {
+		LogError(_("{:s} has cast an invalid spell.").c_str(), player._pName);
+		return sizeof(message);
+	}
 	if (currlevel == 0 && !spelldata[spell].sTownSpell) {
 		LogError(_("{:s} has cast an illegal spell.").c_str(), player._pName);
 		return sizeof(message);
@@ -1071,6 +1075,10 @@ DWORD OnSpellTile(const TCmd *pCmd, Player &player)
 		return sizeof(message);
 
 	auto spell = static_cast<spell_id>(message.wParam1);
+	if (!IsValidSpell(spell)) {
+		LogError(_("{:s} has cast an invalid spell.").c_str(), player._pName);
+		return sizeof(message);
+	}
 	if (currlevel == 0 && !spelldata[spell].sTownSpell) {
 		LogError(_("{:s} has cast an illegal spell.").c_str(), player._pName);
 		return sizeof(message);
@@ -1229,6 +1237,10 @@ DWORD OnSpellMonster(const TCmd *pCmd, Player &player)
 		return sizeof(message);
 
 	auto spell = static_cast<spell_id>(message.wParam2);
+	if (!IsValidSpell(spell)) {
+		LogError(_("{:s} has cast an invalid spell.").c_str(), player._pName);
+		return sizeof(message);
+	}
 	if (currlevel == 0 && !spelldata[spell].sTownSpell) {
 		LogError(_("{:s} has cast an illegal spell.").c_str(), player._pName);
 		return sizeof(message);
@@ -1261,6 +1273,10 @@ DWORD OnSpellPlayer(const TCmd *pCmd, Player &player)
 		return sizeof(message);
 
 	auto spell = static_cast<spell_id>(message.wParam2);
+	if (!IsValidSpell(spell)) {
+		LogError(_("{:s} has cast an invalid spell.").c_str(), player._pName);
+		return sizeof(message);
+	}
 	if (currlevel == 0 && !spelldata[spell].sTownSpell) {
 		LogError(_("{:s} has cast an illegal spell.").c_str(), player._pName);
 		return sizeof(message);