diff --git a/source/meta.zig b/source/meta.zig
index c2ba074..d68537d 100644
--- a/source/meta.zig
+++ b/source/meta.zig
@@ -21,7 +21,7 @@ pub fn UpdateDefaults(comptime input: type, comptime defaults: anytype) type {
         };
 
         var fields: [fieldcount]StructField = undefined;
-        for (inputInfo.Struct.fields) |field, idx| {
+        for (inputInfo.Struct.fields, 0..) |field, idx| {
             fields[idx] = .{
                 .name = field.name,
                 .field_type = field.field_type,
@@ -78,11 +78,11 @@ pub const MutableTuple = struct {
     pub fn TupleType(comptime self: @This()) type {
         comptime {
             var fields: [self.types.len]StructField = undefined;
-            for (self.types) |Type, idx| {
+            for (self.types, 0..) |Type, idx| {
                 var num_buf: [128]u8 = undefined;
                 fields[idx] = .{
                     .name = std.fmt.bufPrint(&num_buf, "{d}", .{idx}) catch unreachable,
-                    .field_type = Type,
+                    .type = Type,
                     .default_value = null,
                     // TODO: is this the right thing to do?
                     .is_comptime = false,
diff --git a/source/noclip.zig b/source/noclip.zig
index 086f650..2d8ae6b 100644
--- a/source/noclip.zig
+++ b/source/noclip.zig
@@ -128,7 +128,7 @@ pub fn CommandParser(
                         return OptionError.UnknownOption;
                     } else {
                         // we have a short flag, which may be multiple fused flags
-                        shortloop: for (arg[1..]) |shorty, idx| {
+                        shortloop: for (arg[1..], 0..) |shorty, idx| {
                             specloop: inline for (spec) |param| {
                                 switch (@TypeOf(param).brand) {
                                     .Option => {
@@ -251,13 +251,13 @@ pub fn CommandParser(
             }
         }
 
-        fn scryTruthiness(alloc: std.mem.Allocator, input: []const u8) !bool {
+        fn scryTruthiness(input: []const u8) bool {
             // empty string is falsy.
             if (input.len == 0) return false;
 
             if (input.len <= 5) {
-                const comp = try std.ascii.allocLowerString(alloc, input);
-                defer alloc.free(comp);
+                var lowerBuf: [5]u8 = undefined;
+                const comp = std.ascii.lowerString(&lowerBuf, input);
 
                 inline for ([_][]const u8{ "false", "no", "0" }) |candidate| {
                     if (std.mem.eql(u8, comp, candidate)) {
@@ -302,7 +302,7 @@ pub fn CommandParser(
                     .Flag => {
                         if (param.envVar) |want| {
                             if (env.get(want)) |value| {
-                                @field(result, param.name) = try scryTruthiness(alloc, value);
+                                @field(result, param.name) = scryTruthiness(value);
                             }
                         }
                     },
@@ -369,7 +369,7 @@ pub fn CommandResult(comptime spec: anytype, comptime UserContext: type) type {
 
             fields[idx] = .{
                 .name = param.name,
-                .field_type = FieldType,
+                .type = FieldType,
                 .default_value = @ptrCast(?*const anyopaque, &param.default),
                 .is_comptime = false,
                 .alignment = @alignOf(FieldType),
@@ -417,7 +417,7 @@ fn RequiredTracker(comptime spec: anytype) type {
                 .Argument, .Option => if (param.required()) {
                     fields[idx] = .{
                         .name = param.name,
-                        .field_type = bool,
+                        .type = bool,
                         .default_value = &false,
                         .is_comptime = false,
                         .alignment = @alignOf(bool),
diff --git a/source/params.zig b/source/params.zig
index d174eca..f130085 100644
--- a/source/params.zig
+++ b/source/params.zig
@@ -32,7 +32,7 @@ pub fn Option(comptime args: ParameterArgs) type {
 
     comptime var result = struct {
         pub const brand: Brand = .Option;
-        pub const mayBeOptional: bool = switch (@typeInfo(args.Output)) {
+        const mayBeOptional: bool = switch (@typeInfo(args.Output)) {
             .Optional => true,
             else => false,
         };
@@ -96,13 +96,18 @@ pub fn Flag(comptime UserContext: type) type {
         pub const ContextType: type = UserContext;
 
         name: []const u8,
-        default: bool = false,
+        default: ?bool = false,
         truthy: ShortLong = .{},
         falsy: ShortLong = .{},
         help: ?[]const u8 = null,
         envVar: ?[]const u8 = null,
         hideResult: bool = false,
         eager: ?*const fn (UserContext, CommandData) anyerror!void = null,
+
+        pub fn required(self: @This()) bool {
+            if (self.default) return true;
+            return false;
+        }
     };
 }
 
@@ -149,7 +154,7 @@ pub fn Argument(comptime args: ParameterArgs) type {
 
     return struct {
         pub const brand: Brand = .Argument;
-        pub const mayBeOptional: bool = switch (@typeInfo(args.Output)) {
+        const mayBeOptional: bool = switch (@typeInfo(args.Output)) {
             .Optional => true,
             else => false,
         };