diff --git a/Sources/ForgejoKit/Services/PullRequestService.swift b/Sources/ForgejoKit/Services/PullRequestService.swift
index 2ad555b..9fa8146 100644
--- a/Sources/ForgejoKit/Services/PullRequestService.swift
+++ b/Sources/ForgejoKit/Services/PullRequestService.swift
@@ -41,8 +41,8 @@ public final class PullRequestService: Sendable {
         enum CodingKeys: String, CodingKey {
             case method = "Do"
             case deleteBranchAfterMerge = "delete_branch_after_merge"
-            case mergeTitleField = "merge_title_field"
-            case mergeMessageField = "merge_message_field"
+            case mergeTitleField = "MergeTitleField"
+            case mergeMessageField = "MergeMessageField"
         }
     }