diff --git a/src/main/java/com/minelittlepony/api/model/armour/ArmorModelRegistry.java b/src/main/java/com/minelittlepony/api/model/armour/ArmorModelRegistry.java
index 2d062a40..851742f6 100644
--- a/src/main/java/com/minelittlepony/api/model/armour/ArmorModelRegistry.java
+++ b/src/main/java/com/minelittlepony/api/model/armour/ArmorModelRegistry.java
@@ -18,7 +18,7 @@ public interface ArmorModelRegistry {
         if (id.getNamespace().equals("minecraft")) {
             return Optional.empty();
         }
-        return REGISTRY.computeIfAbsent(id.withPath(p -> "models/armor/" + layer.name().toLowerCase() + "_" + p + ".json"), i -> {
+        return REGISTRY.computeIfAbsent(id.withPath(p -> "models/armor/" + layer.name().toLowerCase(Locale.ROOT) + "_" + p + ".json"), i -> {
             return Optional.of(Mson.getInstance().registerModel(i, PonyArmourModel::new));
         }).filter(key -> key.getModelData().isPresent());
     }