diff --git a/github/repos.go b/github/repos.go
index 1841cd6c15..499ed67786 100644
--- a/github/repos.go
+++ b/github/repos.go
@@ -70,10 +70,10 @@ type Repository struct {
 	AllowForking              *bool           `json:"allow_forking,omitempty"`
 	DeleteBranchOnMerge       *bool           `json:"delete_branch_on_merge,omitempty"`
 	UseSquashPRTitleAsDefault *bool           `json:"use_squash_pr_title_as_default,omitempty"`
-	SquashMergeCommitTitle    *string         `json:"squash_merge_commit_title,omitempty"`
-	SquashMergeCommitMessage  *string         `json:"squash_merge_commit_message,omitempty"`
-	MergeCommitTitle          *string         `json:"merge_commit_title,omitempty"`
-	MergeCommitMessage        *string         `json:"merge_commit_message,omitempty"`
+	SquashMergeCommitTitle    *string         `json:"squash_merge_commit_title,omitempty"`   // Can be one of: "PR_TITLE", "COMMIT_OR_PR_TITLE"
+	SquashMergeCommitMessage  *string         `json:"squash_merge_commit_message,omitempty"` // Can be one of: "PR_BODY", "COMMIT_MESSAGES", "BLANK"
+	MergeCommitTitle          *string         `json:"merge_commit_title,omitempty"`          // Can be one of: "PR_TITLE", "MERGE_MESSAGE"
+	MergeCommitMessage        *string         `json:"merge_commit_message,omitempty"`        // Can be one of: "PR_BODY", "PR_TITLE", "BLANK"
 	Topics                    []string        `json:"topics,omitempty"`
 	Archived                  *bool           `json:"archived,omitempty"`
 	Disabled                  *bool           `json:"disabled,omitempty"`