diff --git a/include/git2/worktree.h b/include/git2/worktree.h
index e3bafc3d0..d3fa88e3f 100644
--- a/include/git2/worktree.h
+++ b/include/git2/worktree.h
@@ -77,7 +77,7 @@ GIT_EXTERN(int) git_worktree_validate(const git_worktree *wt);
 typedef struct git_worktree_add_options {
 	unsigned int version;
 
-	char lock; /**< lock newly created worktree */
+	int lock; /**< lock newly created worktree */
 } git_worktree_add_options;
 
 #define GIT_WORKTREE_ADD_OPTIONS_VERSION 1