diff --git a/src/main/java/cc/fascinated/controller/PlayerController.java b/src/main/java/cc/fascinated/controller/PlayerController.java
index 338f465..50a8ac6 100644
--- a/src/main/java/cc/fascinated/controller/PlayerController.java
+++ b/src/main/java/cc/fascinated/controller/PlayerController.java
@@ -2,6 +2,7 @@ package cc.fascinated.controller;
 
 import cc.fascinated.model.player.Player;
 import cc.fascinated.model.player.Skin;
+import cc.fascinated.model.response.impl.InvalidPartResponse;
 import cc.fascinated.model.response.impl.PlayerNotFoundResponse;
 import cc.fascinated.service.PlayerService;
 import cc.fascinated.util.PlayerUtils;
@@ -39,7 +40,7 @@ public class PlayerController {
     }
 
     @GetMapping(value = "/{part}/{id}")
-    public ResponseEntity<byte[]> getPlayerHead(@PathVariable String part,
+    public ResponseEntity<?> getPlayerHead(@PathVariable String part,
                                                 @PathVariable String id,
                                                 @RequestParam(required = false, defaultValue = "250") int size) {
         Player player = playerManagerService.getPlayer(id);
@@ -47,9 +48,10 @@ public class PlayerController {
         if (player != null) { // The player exists
             Skin skin = player.getSkin();
             Skin.Parts skinPart = Skin.Parts.fromName(part);
-            if (skinPart != null) { // The part exists
-                partBytes = PlayerUtils.getSkinPartBytes(skin, skinPart, size);
+            if (skinPart == null) { // Unknown part name
+                return new InvalidPartResponse().toResponseEntity();
             }
+            partBytes = PlayerUtils.getSkinPartBytes(skin, skinPart, size);
         }
         if (partBytes == null) { // Fallback to the default head
             partBytes = PlayerUtils.getSkinPartBytes(Skin.DEFAULT_SKIN, Skin.Parts.HEAD, size);
diff --git a/src/main/java/cc/fascinated/model/response/impl/InvalidPartResponse.java b/src/main/java/cc/fascinated/model/response/impl/InvalidPartResponse.java
new file mode 100644
index 0000000..132e643
--- /dev/null
+++ b/src/main/java/cc/fascinated/model/response/impl/InvalidPartResponse.java
@@ -0,0 +1,11 @@
+package cc.fascinated.model.response.impl;
+
+import cc.fascinated.model.response.Response;
+import org.springframework.http.HttpStatus;
+
+public class InvalidPartResponse extends Response {
+
+    public InvalidPartResponse() {
+        super(HttpStatus.NOT_FOUND, "Invalid part name.");
+    }
+}