diff --git a/git.zig b/git.zig
index 090f69e8fe9574c901c3bd1ba5fe83abe39f7a69..52fb0841ed3eac07b864834e34f35bf15fe88444 100644
--- a/git.zig
+++ b/git.zig
@@ -166,12 +166,7 @@ pub fn parseTree(alloc: std.mem.Allocator, treefile: string) !Tree {
         inline for (std.meta.fields(Tree.Object.Id)) |item| {
             if (std.mem.eql(u8, item.name, @tagName(otype))) {
                 try children.append(.{
-                    .mode = .{
-                        .type = @intToEnum(Tree.Object.Type, try std.fmt.parseInt(u16, mode[0..3], 10)),
-                        .perm_user = @bitCast(Tree.Object.Perm, try std.fmt.parseInt(u3, mode[3..][0..1], 8)),
-                        .perm_group = @bitCast(Tree.Object.Perm, try std.fmt.parseInt(u3, mode[4..][0..1], 8)),
-                        .perm_other = @bitCast(Tree.Object.Perm, try std.fmt.parseInt(u3, mode[5..][0..1], 8)),
-                    },
+                    .mode = try parseTreeMode(mode),
                     .id = @unionInit(Tree.Object.Id, item.name, item.type{ .id = id }),
                     .name = name,
                 });
@@ -183,6 +178,16 @@ pub fn parseTree(alloc: std.mem.Allocator, treefile: string) !Tree {
     };
 }
 
+fn parseTreeMode(input: string) !Tree.Object.Mode {
+    std.debug.assert(input.len == 6);
+    return .{
+        .type = @intToEnum(Tree.Object.Type, try std.fmt.parseInt(u16, input[0..3], 10)),
+        .perm_user = @bitCast(Tree.Object.Perm, try std.fmt.parseInt(u3, input[3..][0..1], 8)),
+        .perm_group = @bitCast(Tree.Object.Perm, try std.fmt.parseInt(u3, input[4..][0..1], 8)),
+        .perm_other = @bitCast(Tree.Object.Perm, try std.fmt.parseInt(u3, input[5..][0..1], 8)),
+    };
+}
+
 pub const Tree = struct {
     children: []const Object,