diff --git a/src/Library/CreatureData/CreatureSpecies.cpp b/src/Library/CreatureData/CreatureSpecies.cpp
index 04f2ef5..e4006ef 100644
--- a/src/Library/CreatureData/CreatureSpecies.cpp
+++ b/src/Library/CreatureData/CreatureSpecies.cpp
@@ -9,13 +9,13 @@ CreatureSpecies::CreatureSpecies(uint16_t id, std::string name, const SpeciesVar
 
 bool CreatureSpecies::HasVariant(const std::string& name) const {
     auto key = name;
-    std::transform(key.begin(), key.end(), key.end(), ::tolower);
+    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
     return _variants.find(key) != _variants.end();
 }
 
 bool CreatureSpecies::TryGetVariant(const std::string& name, const SpeciesVariant*& out) const {
     auto key = name;
-    std::transform(key.begin(), key.end(), key.end(), ::tolower);
+    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
     auto find = _variants.find(key);
     if (find != _variants.end()) {
         out = find->second;
@@ -26,13 +26,13 @@ bool CreatureSpecies::TryGetVariant(const std::string& name, const SpeciesVarian
 
 const SpeciesVariant* CreatureSpecies::GetVariant(const std::string& name) const {
     auto key = name;
-    std::transform(key.begin(), key.end(), key.end(), ::tolower);
+    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
     return _variants.at(key);
 }
 
 void CreatureSpecies::SetVariant(const std::string& name, const SpeciesVariant* variant) {
     auto key = name;
-    std::transform(key.begin(), key.end(), key.end(), ::tolower);
+    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
     auto find = _variants.find(key);
     if (find != _variants.end()) {
         delete find->second;