diff --git a/DysonNetwork.Sphere/ActivityPub/ActivityPubSignatureService.cs b/DysonNetwork.Sphere/ActivityPub/ActivityPubSignatureService.cs
index db8c722..63367a8 100644
--- a/DysonNetwork.Sphere/ActivityPub/ActivityPubSignatureService.cs
+++ b/DysonNetwork.Sphere/ActivityPub/ActivityPubSignatureService.cs
@@ -226,6 +226,10 @@ public class ActivityPubSignatureService(
             {
                 sb.Append(Domain);
             }
+            else if (header == "content-type")
+            {
+                continue;
+            }
             else
             {
                 if (context.Request.Headers.TryGetValue(header, out var values))