diff --git a/vlib/builtin/string_interpolation.v b/vlib/builtin/string_interpolation.v
index 8e6c23b8e8..0f3b219d8b 100644
--- a/vlib/builtin/string_interpolation.v
+++ b/vlib/builtin/string_interpolation.v
@@ -414,14 +414,16 @@ fn (data StrIntpData) get_fmt_format(mut sb strings.Builder) {
 			.si_g32 {
 				// println("HERE: g32")
 				if use_default_str {
-					mut f := data.d.d_f32.strg()
-					if upper_case {
-						tmp := f
-						f = f.to_upper()
-						tmp.free()
+					$if !nofloat ? {
+						mut f := data.d.d_f32.strg()
+						if upper_case {
+							tmp := f
+							f = f.to_upper()
+							tmp.free()
+						}
+						sb.write_string(f)
+						f.free()
 					}
-					sb.write_string(f)
-					f.free()
 				} else {
 					// Manage +/-0
 					if data.d.d_f32 == strconv.single_plus_zero {
@@ -482,14 +484,16 @@ fn (data StrIntpData) get_fmt_format(mut sb strings.Builder) {
 			.si_g64 {
 				// println("HERE: g64")
 				if use_default_str {
-					mut f := data.d.d_f64.strg()
-					if upper_case {
-						tmp := f
-						f = f.to_upper()
-						tmp.free()
+					$if !nofloat ? {
+						mut f := data.d.d_f64.strg()
+						if upper_case {
+							tmp := f
+							f = f.to_upper()
+							tmp.free()
+						}
+						sb.write_string(f)
+						f.free()
 					}
-					sb.write_string(f)
-					f.free()
 				} else {
 					// Manage +/-0
 					if data.d.d_f64 == strconv.double_plus_zero {
diff --git a/vlib/v/pref/pref.v b/vlib/v/pref/pref.v
index 12b551598c..29a13fa857 100644
--- a/vlib/v/pref/pref.v
+++ b/vlib/v/pref/pref.v
@@ -290,36 +290,36 @@ pub fn parse_args(known_external_commands []string, args []string) (&Preferences
 					}
 					'boehm_full' {
 						res.gc_mode = .boehm_full
-						parse_define(mut res, 'gcboehm')
-						parse_define(mut res, 'gcboehm_full')
+						res.parse_define('gcboehm')
+						res.parse_define('gcboehm_full')
 					}
 					'boehm_incr' {
 						res.gc_mode = .boehm_incr
-						parse_define(mut res, 'gcboehm')
-						parse_define(mut res, 'gcboehm_incr')
+						res.parse_define('gcboehm')
+						res.parse_define('gcboehm_incr')
 					}
 					'boehm_full_opt' {
 						res.gc_mode = .boehm_full_opt
-						parse_define(mut res, 'gcboehm')
-						parse_define(mut res, 'gcboehm_full')
-						parse_define(mut res, 'gcboehm_opt')
+						res.parse_define('gcboehm')
+						res.parse_define('gcboehm_full')
+						res.parse_define('gcboehm_opt')
 					}
 					'boehm_incr_opt' {
 						res.gc_mode = .boehm_incr_opt
-						parse_define(mut res, 'gcboehm')
-						parse_define(mut res, 'gcboehm_incr')
-						parse_define(mut res, 'gcboehm_opt')
+						res.parse_define('gcboehm')
+						res.parse_define('gcboehm_incr')
+						res.parse_define('gcboehm_opt')
 					}
 					'boehm' {
 						res.gc_mode = .boehm_full_opt // default mode
-						parse_define(mut res, 'gcboehm')
-						parse_define(mut res, 'gcboehm_full')
-						parse_define(mut res, 'gcboehm_opt')
+						res.parse_define('gcboehm')
+						res.parse_define('gcboehm_full')
+						res.parse_define('gcboehm_opt')
 					}
 					'boehm_leak' {
 						res.gc_mode = .boehm_leak
-						parse_define(mut res, 'gcboehm')
-						parse_define(mut res, 'gcboehm_leak')
+						res.parse_define('gcboehm')
+						res.parse_define('gcboehm_leak')
 					}
 					else {
 						eprintln('unknown garbage collection mode `-gc $gc_mode`, supported modes are:`')
@@ -529,7 +529,7 @@ pub fn parse_args(known_external_commands []string, args []string) (&Preferences
 			'-d', '-define' {
 				if current_args.len > 1 {
 					define := current_args[1]
-					parse_define(mut res, define)
+					res.parse_define(define)
 				}
 				i++
 			}
@@ -631,7 +631,7 @@ pub fn parse_args(known_external_commands []string, args []string) (&Preferences
 		}
 	}
 	if res.is_debug {
-		parse_define(mut res, 'debug')
+		res.parse_define('debug')
 	}
 
 	// res.use_cache = true
@@ -818,7 +818,7 @@ pub fn get_host_arch() Arch {
 	return Arch(C.__V_architecture)
 }
 
-fn parse_define(mut prefs Preferences, define string) {
+fn (mut prefs Preferences) parse_define(define string) {
 	define_parts := define.split('=')
 	if !(prefs.is_debug && define == 'debug') {
 		prefs.build_options << '-d $define'