diff --git a/app/src/main/java/com/mattintech/simplelogupload/constant/NetworkConstants.java b/app/src/main/java/com/mattintech/simplelogupload/constant/NetworkConstants.java
index 2e42661..105611d 100644
--- a/app/src/main/java/com/mattintech/simplelogupload/constant/NetworkConstants.java
+++ b/app/src/main/java/com/mattintech/simplelogupload/constant/NetworkConstants.java
@@ -14,7 +14,7 @@ public class NetworkConstants {
     public static final String PARAM_EXPIRY_HOURS = "expiry_hours";
     
     // Authentication
-    public static final String CLIENT_KEY_HEADER = "client-key";
+    public static final String CLIENT_KEY_HEADER = "X-Client-Key";
     
     // Default values
     public static final int DEFAULT_MAX_DOWNLOADS = 1;
diff --git a/app/src/main/java/com/mattintech/simplelogupload/controller/UploadController.java b/app/src/main/java/com/mattintech/simplelogupload/controller/UploadController.java
index a4ce8c1..c1ed0b7 100644
--- a/app/src/main/java/com/mattintech/simplelogupload/controller/UploadController.java
+++ b/app/src/main/java/com/mattintech/simplelogupload/controller/UploadController.java
@@ -109,6 +109,7 @@ public class UploadController {
         String clientKey = PreferencesUtil.getClientKey(context);
         
         Log.d(TAG, "Using server URL: " + serverUrl);
+        Log.d(TAG, "Adding header '" + NetworkConstants.CLIENT_KEY_HEADER + "' with value: " + clientKey);
         
         // Build request with client-key header
         Request request = new Request.Builder()
@@ -159,6 +160,7 @@ public class UploadController {
                     if (response.code() == 401 || response.code() == 403) {
                         errorMsg = "Authentication failed. Please check client key.";
                         Log.e(TAG, "Authentication error: " + response.code() + ", Body: " + errorBody);
+                        Log.e(TAG, "Header sent: " + NetworkConstants.CLIENT_KEY_HEADER + ": " + clientKey);
                     } else {
                         errorMsg = "Upload failed, Response code: " + response.code();
                         Log.e(TAG, errorMsg + ", Body: " + errorBody);