diff --git a/cmd/tools/vfmt.v b/cmd/tools/vfmt.v
index 10281d8796..fdbc35daee 100644
--- a/cmd/tools/vfmt.v
+++ b/cmd/tools/vfmt.v
@@ -74,7 +74,7 @@ fn main() {
 		eprintln('vfmt env_vflags_and_os_args: ' + args.str())
 		eprintln('vfmt possible_files: ' + possible_files.str())
 	}
-	var files := []string
+	mut files := []string
 	for file in possible_files {
 		if !file.ends_with('.v') && !file.ends_with('.vv') {
 			verror('v fmt can only be used on .v files.\nOffending file: "$file"')
@@ -90,16 +90,16 @@ fn main() {
 		vhelp.show_topic('fmt')
 		exit(0)
 	}
-	var cli_args_no_files := []string
+	mut cli_args_no_files := []string
 	for a in os.args {
 		if !(a in files) {
 			cli_args_no_files << a
 		}
 	}
-	var errors := 0
+	mut errors := 0
 	for file in files {
 		fpath := os.real_path(file)
-		var worker_command_array := cli_args_no_files.clone()
+		mut worker_command_array := cli_args_no_files.clone()
 		worker_command_array << ['-worker', fpath]
 		worker_cmd := worker_command_array.join(' ')
 		if foptions.is_verbose {
@@ -252,8 +252,8 @@ fn file_to_target_os(file string) string {
 }
 
 fn file_to_mod_name_and_is_module_file(file string) (string, bool) {
-	var mod_name := 'main'
-	var is_module_file := false
+	mut mod_name := 'main'
+	mut is_module_file := false
 	flines := read_source_lines(file) or {
 		return mod_name, is_module_file
 	}
@@ -287,7 +287,7 @@ fn get_compile_name_of_potential_v_project(file string) string {
 	all_files_in_pfolder := os.ls(pfolder) or {
 		panic(err)
 	}
-	var vfiles := []string
+	mut vfiles := []string
 	for f in all_files_in_pfolder {
 		vf := os.join_path(pfolder, f)
 		if f.starts_with('.') || !f.ends_with('.v') || os.is_dir(vf) {
@@ -304,7 +304,7 @@ fn get_compile_name_of_potential_v_project(file string) string {
 	// containing `fn main` then the folder contains multiple standalone
 	// v programs. If only one contains `fn main` then the folder is
 	// a project folder, that should be compiled with `v pfolder`.
-	var main_fns := 0
+	mut main_fns := 0
 	for f in vfiles {
 		slines := read_source_lines(f) or {
 			panic(err)
diff --git a/cmd/v/v.v b/cmd/v/v.v
index 7ee0187532..241be0d91b 100644
--- a/cmd/v/v.v
+++ b/cmd/v/v.v
@@ -109,9 +109,9 @@ fn main() {
 }
 
 fn parse_args(args []string) (&pref.Preferences, string) {
-	var res := &pref.Preferences{}
-	var command := ''
-	var command_pos := 0
+	mut res := &pref.Preferences{}
+	mut command := ''
+	mut command_pos := 0
 	// for i, arg in args {
 	for i := 0; i < args.len; i++ {
 		arg := args[i]
@@ -198,7 +198,7 @@ fn parse_args(args []string) (&pref.Preferences, string) {
 				i++
 			}
 			else {
-				var should_continue := false
+				mut should_continue := false
 				for flag_with_param in list_of_flags_with_param {
 					if '-$flag_with_param' == arg {
 						should_continue = true
@@ -254,8 +254,8 @@ fn create_symlink() {
 		return
 	}
 	vexe := pref.vexe_path()
-	var link_path := '/usr/local/bin/v'
-	var ret := os.exec('ln -sf $vexe $link_path') or {
+	mut link_path := '/usr/local/bin/v'
+	mut ret := os.exec('ln -sf $vexe $link_path') or {
 		panic(err)
 	}
 	if ret.exit_code == 0 {
diff --git a/vlib/v/builder/builder.v b/vlib/v/builder/builder.v
index aff52d8184..87d2c0b78c 100644
--- a/vlib/v/builder/builder.v
+++ b/vlib/v/builder/builder.v
@@ -47,7 +47,7 @@ pub fn new_builder(pref &pref.Preferences) Builder {
 
 // parse all deps from already parsed files
 pub fn (b mut Builder) parse_imports() {
-	var done_imports := []string
+	mut done_imports := []string
 	// NB: b.parsed_files is appended in the loop,
 	// so we can not use the shorter `for in` form.
 	for i := 0; i < b.parsed_files.len; i++ {
@@ -97,7 +97,7 @@ pub fn (b mut Builder) resolve_deps() {
 		eprintln(deps_resolved.display())
 		eprintln('------------------------------------------')
 	}
-	var mods := []string
+	mut mods := []string
 	for node in deps_resolved.nodes {
 		mods << node.name
 	}
@@ -106,7 +106,7 @@ pub fn (b mut Builder) resolve_deps() {
 		eprintln(mods.str())
 		eprintln('-------------------------------')
 	}
-	var reordered_parsed_files := []ast.File
+	mut reordered_parsed_files := []ast.File
 	for m in mods {
 		for pf in b.parsed_files {
 			if m == pf.mod.name {
@@ -120,11 +120,11 @@ pub fn (b mut Builder) resolve_deps() {
 
 // graph of all imported modules
 pub fn (b &Builder) import_graph() &depgraph.DepGraph {
-	var builtins := util.builtin_module_parts
+	mut builtins := util.builtin_module_parts
 	builtins << 'builtin'
-	var graph := depgraph.new_dep_graph()
+	mut graph := depgraph.new_dep_graph()
 	for p in b.parsed_files {
-		var deps := []string
+		mut deps := []string
 		if p.mod.name !in builtins {
 			deps << 'builtin'
 		}
@@ -137,7 +137,7 @@ pub fn (b &Builder) import_graph() &depgraph.DepGraph {
 }
 
 pub fn (b Builder) v_files_from_dir(dir string) []string {
-	var res := []string
+	mut res := []string
 	if !os.exists(dir) {
 		if dir == 'compiler' && os.is_dir('vlib') {
 			println('looks like you are trying to build V with an old command')
@@ -147,7 +147,7 @@ pub fn (b Builder) v_files_from_dir(dir string) []string {
 	} else if !os.is_dir(dir) {
 		verror("$dir isn't a directory!")
 	}
-	var files := os.ls(dir) or {
+	mut files := os.ls(dir) or {
 		panic(err)
 	}
 	if b.pref.is_verbose {
@@ -168,7 +168,7 @@ pub fn (b Builder) v_files_from_dir(dir string) []string {
 			continue
 		}
 		if b.pref.compile_defines_all.len > 0 && file.contains('_d_') {
-			var allowed := false
+			mut allowed := false
 			for cdefine in b.pref.compile_defines {
 				file_postfix := '_d_${cdefine}.v'
 				if file.ends_with(file_postfix) {
@@ -246,7 +246,7 @@ pub fn (b Builder) find_module_path(mod, fpath string) ?string {
 	// support @VROOT/v.mod relative paths:
 	vmod_file_location := vmod.mod_file_cacher.get(fpath)
 	mod_path := module_path(mod)
-	var module_lookup_paths := []string
+	mut module_lookup_paths := []string
 	if vmod_file_location.vmod_file.len != 0 && !(vmod_file_location.vmod_folder in b.module_search_paths) {
 		module_lookup_paths << vmod_file_location.vmod_folder
 	}
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index f8dcf5f230..e10662b1bb 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -1947,7 +1947,7 @@ fn (mut g Gen) struct_init(struct_init ast.StructInit) {
 	} else {
 		g.writeln('($styp){')
 	}
-	// var fields := []string
+	// mut fields := []string
 	mut inited_fields := []string // TODO this is done in checker, move to ast node
 	/*
 	if struct_init.fields.len == 0 && struct_init.exprs.len > 0 {
diff --git a/vlib/v/gen/x64/tests/x64_test.v b/vlib/v/gen/x64/tests/x64_test.v
index b766d97dc5..4223300201 100644
--- a/vlib/v/gen/x64/tests/x64_test.v
+++ b/vlib/v/gen/x64/tests/x64_test.v
@@ -8,7 +8,7 @@ fn test_x64() {
 		eprintln('x64 tests can only be run on Linux for now.')
 		exit(0)
 	}
-	var bench := benchmark.new_benchmark()
+	mut bench := benchmark.new_benchmark()
 	vexe := os.getenv('VEXE')
 	vroot := os.dir(vexe)
 	dir := os.join_path(vroot, 'vlib/v/gen/x64/tests')
@@ -45,11 +45,11 @@ fn test_x64() {
 			eprintln(res.output)
 			continue
 		}
-		var expected := os.read_file('$dir/${test}.out') or {
+		mut expected := os.read_file('$dir/${test}.out') or {
 			panic(err)
 		}
 		expected = expected.trim_space().trim('\n').replace('\r\n', '\n')
-		var found := res.output.trim_space().trim('\n').replace('\r\n', '\n')
+		mut found := res.output.trim_space().trim('\n').replace('\r\n', '\n')
 		// remove ACK char TODO fix this in x64
 		buf := [byte(0x06)]
 		ack := string(buf)
diff --git a/vlib/v/parser/assign.v b/vlib/v/parser/assign.v
index 9107a8e881..f5146bf666 100644
--- a/vlib/v/parser/assign.v
+++ b/vlib/v/parser/assign.v
@@ -7,7 +7,7 @@ import v.ast
 import v.table
 import v.token
 
-fn (var p Parser) assign_stmt() ast.Stmt {
+fn (mut p Parser) assign_stmt() ast.Stmt {
 	is_static := p.tok.kind == .key_static
 	if is_static {
 		p.next()
@@ -51,7 +51,7 @@ fn (var p Parser) assign_stmt() ast.Stmt {
 }
 
 // TODO: is it possible to merge with AssignStmt?
-pub fn (var p Parser) assign_expr(left ast.Expr) ast.AssignExpr {
+pub fn (mut p Parser) assign_expr(left ast.Expr) ast.AssignExpr {
 	op := p.tok.kind
 	pos := p.tok.position()
 	p.next()
@@ -72,8 +72,8 @@ pub fn (var p Parser) assign_expr(left ast.Expr) ast.AssignExpr {
 	return node
 }
 
-fn (var p Parser) parse_assign_lhs() []ast.Ident {
-	var idents := []ast.Ident
+fn (mut p Parser) parse_assign_lhs() []ast.Ident {
+	mut idents := []ast.Ident
 	for {
 		is_mut := p.tok.kind == .key_mut || p.tok.kind == .key_var
 		if is_mut {
@@ -83,7 +83,7 @@ fn (var p Parser) parse_assign_lhs() []ast.Ident {
 		if is_static {
 			p.check(.key_static)
 		}
-		var ident := p.parse_ident(false, false)
+		mut ident := p.parse_ident(false, false)
 		ident.is_mut = is_mut
 		ident.info = ast.IdentVar{
 			is_mut: is_mut
@@ -100,8 +100,8 @@ fn (var p Parser) parse_assign_lhs() []ast.Ident {
 }
 
 // right hand side of `=` or `:=` in `a,b,c := 1,2,3`
-fn (var p Parser) parse_assign_rhs() []ast.Expr {
-	var exprs := []ast.Expr
+fn (mut p Parser) parse_assign_rhs() []ast.Expr {
+	mut exprs := []ast.Expr
 	for {
 		expr := p.expr(0)
 		exprs << expr
diff --git a/vlib/v/parser/comptime.v b/vlib/v/parser/comptime.v
index 1be5d9623c..d4ca59d116 100644
--- a/vlib/v/parser/comptime.v
+++ b/vlib/v/parser/comptime.v
@@ -15,7 +15,7 @@ const (
 )
 
 // // #include, #flag, #v
-fn (p mut Parser) hash() ast.HashStmt {
+fn (mut p Parser) hash() ast.HashStmt {
 	val := p.tok.lit
 	p.next()
 	if val.starts_with('flag') {
@@ -56,7 +56,7 @@ fn (p mut Parser) hash() ast.HashStmt {
 	}
 }
 
-fn (p mut Parser) comp_if() ast.CompIf {
+fn (mut p Parser) comp_if() ast.CompIf {
 	pos := p.tok.position()
 	p.next()
 	p.check(.key_if)
diff --git a/vlib/v/parser/containers.v b/vlib/v/parser/containers.v
index 157a18d76f..bff05735df 100644
--- a/vlib/v/parser/containers.v
+++ b/vlib/v/parser/containers.v
@@ -7,15 +7,15 @@ import v.ast
 import v.table
 import v.token
 
-fn (var p Parser) array_init() ast.ArrayInit {
+fn (mut p Parser) array_init() ast.ArrayInit {
 	first_pos := p.tok.position()
-	var last_pos := token.Position{}
+	mut last_pos := token.Position{}
 	p.check(.lsbr)
 	// p.warn('array_init() exp=$p.expected_type')
-	var array_type := table.void_type
-	var elem_type := table.void_type
-	var exprs := []ast.Expr
-	var is_fixed := false
+	mut array_type := table.void_type
+	mut elem_type := table.void_type
+	mut exprs := []ast.Expr
+	mut is_fixed := false
 	if p.tok.kind == .rsbr {
 		// []typ => `[]` and `typ` must be on the same line
 		line_nr := p.tok.line_nr
@@ -93,10 +93,10 @@ fn (var p Parser) array_init() ast.ArrayInit {
 	}
 }
 
-fn (var p Parser) map_init() ast.MapInit {
+fn (mut p Parser) map_init() ast.MapInit {
 	pos := p.tok.position()
-	var keys := []ast.Expr
-	var vals := []ast.Expr
+	mut keys := []ast.Expr
+	mut vals := []ast.Expr
 	for p.tok.kind != .rcbr && p.tok.kind != .eof {
 		// p.check(.str)
 		key := p.expr(0)
diff --git a/vlib/v/parser/for.v b/vlib/v/parser/for.v
index fa1545d53c..3d6e8b3198 100644
--- a/vlib/v/parser/for.v
+++ b/vlib/v/parser/for.v
@@ -7,7 +7,7 @@ import v.ast
 import v.table
 import v.token
 
-fn (var p Parser) for_stmt() ast.Stmt {
+fn (mut p Parser) for_stmt() ast.Stmt {
 	p.check(.key_for)
 	pos := p.tok.position()
 	p.open_scope()
@@ -27,13 +27,13 @@ fn (var p Parser) for_stmt() ast.Stmt {
 		p.error('`var` is not needed in for loops')
 	} else if p.peek_tok.kind in [.decl_assign, .assign, .semicolon] || p.tok.kind == .semicolon {
 		// `for i := 0; i < 10; i++ {`
-		var init := ast.Stmt{}
-		var cond := p.new_true_expr()
+		mut init := ast.Stmt{}
+		mut cond := p.new_true_expr()
 		// mut inc := ast.Stmt{}
-		var inc := ast.Expr{}
-		var has_init := false
-		var has_cond := false
-		var has_inc := false
+		mut inc := ast.Expr{}
+		mut has_init := false
+		mut has_cond := false
+		mut has_inc := false
 		if p.peek_tok.kind in [.assign, .decl_assign] {
 			init = p.assign_stmt()
 			has_init = true
@@ -67,8 +67,8 @@ fn (var p Parser) for_stmt() ast.Stmt {
 		}
 	} else if p.peek_tok.kind in [.key_in, .comma] {
 		// `for i in vals`, `for i in start .. end`
-		var key_var_name := ''
-		var val_var_name := p.check_name()
+		mut key_var_name := ''
+		mut val_var_name := p.check_name()
 		if p.tok.kind == .comma {
 			p.check(.comma)
 			key_var_name = val_var_name
@@ -95,8 +95,8 @@ fn (var p Parser) for_stmt() ast.Stmt {
 		// 0 .. 10
 		// start := p.tok.lit.int()
 		// TODO use RangeExpr
-		var high_expr := ast.Expr{}
-		var is_range := false
+		mut high_expr := ast.Expr{}
+		mut is_range := false
 		if p.tok.kind == .dotdot {
 			is_range = true
 			p.check(.dotdot)
diff --git a/vlib/v/parser/if.v b/vlib/v/parser/if.v
index 4bf0db56b0..ab3df710e9 100644
--- a/vlib/v/parser/if.v
+++ b/vlib/v/parser/if.v
@@ -7,14 +7,14 @@ import v.ast
 import v.table
 import v.token
 
-fn (var p Parser) if_expr() ast.IfExpr {
+fn (mut p Parser) if_expr() ast.IfExpr {
 	pos := p.tok.position()
-	var branches := []ast.IfBranch
-	var has_else := false
+	mut branches := []ast.IfBranch
+	mut has_else := false
 	for p.tok.kind in [.key_if, .key_else] {
 		p.inside_if = true
 		branch_pos := p.tok.position()
-		var comment := ast.Comment{}
+		mut comment := ast.Comment{}
 		if p.tok.kind == .key_if {
 			p.check(.key_if)
 		} else {
@@ -36,8 +36,8 @@ fn (var p Parser) if_expr() ast.IfExpr {
 				break
 			}
 		}
-		var cond := ast.Expr{}
-		var is_or := false
+		mut cond := ast.Expr{}
+		mut is_or := false
 		// `if x := opt() {`
 		if p.peek_tok.kind == .decl_assign {
 			is_or = true
@@ -78,26 +78,26 @@ fn (var p Parser) if_expr() ast.IfExpr {
 	}
 }
 
-fn (var p Parser) match_expr() ast.MatchExpr {
+fn (mut p Parser) match_expr() ast.MatchExpr {
 	match_first_pos := p.tok.position()
 	p.inside_match = true
 	p.check(.key_match)
 	is_mut := p.tok.kind in [.key_mut, .key_var]
-	var is_sum_type := false
+	mut is_sum_type := false
 	if is_mut {
 		p.next()
 	}
 	cond := p.expr(0)
 	p.inside_match = false
 	p.check(.lcbr)
-	var branches := []ast.MatchBranch
+	mut branches := []ast.MatchBranch
 	for {
 		branch_first_pos := p.tok.position()
 		comment := p.check_comment()		// comment before {}
-		var exprs := []ast.Expr
+		mut exprs := []ast.Expr
 		p.open_scope()
 		// final else
-		var is_else := false
+		mut is_else := false
 		if p.tok.kind == .key_else {
 			is_else = true
 			p.next()
@@ -111,7 +111,7 @@ fn (var p Parser) match_expr() ast.MatchExpr {
 			x := ast.Type{
 				typ: typ
 			}
-			var expr := ast.Expr{}
+			mut expr := ast.Expr{}
 			expr = x
 			exprs << expr
 			p.scope.register('it', ast.Var{
@@ -125,7 +125,7 @@ fn (var p Parser) match_expr() ast.MatchExpr {
 			}
 			is_sum_type = true
 			// Make sure a variable used for the sum type match
-			var var_name := ''
+			mut var_name := ''
 			match cond {
 				ast.Ident {
 					var_name = it.name
diff --git a/vlib/v/parser/parse_type.v b/vlib/v/parser/parse_type.v
index 36c437726d..22e93f074e 100644
--- a/vlib/v/parser/parse_type.v
+++ b/vlib/v/parser/parse_type.v
@@ -5,7 +5,7 @@ module parser
 // that can be found in the LICENSE file.
 import v.table
 
-pub fn (p mut Parser) parse_array_type() table.Type {
+pub fn (mut p Parser) parse_array_type() table.Type {
 	p.check(.lsbr)
 	// fixed array
 	if p.tok.kind == .number {
@@ -19,7 +19,7 @@ pub fn (p mut Parser) parse_array_type() table.Type {
 	// array
 	p.check(.rsbr)
 	elem_type := p.parse_type()
-	var nr_dims := 1
+	mut nr_dims := 1
 	for p.tok.kind == .lsbr {
 		p.check(.lsbr)
 		p.check(.rsbr)
@@ -29,7 +29,7 @@ pub fn (p mut Parser) parse_array_type() table.Type {
 	return table.new_type(idx)
 }
 
-pub fn (p mut Parser) parse_map_type() table.Type {
+pub fn (mut p Parser) parse_map_type() table.Type {
 	p.next()
 	if p.tok.kind != .lsbr {
 		return table.map_type
@@ -47,9 +47,9 @@ pub fn (p mut Parser) parse_map_type() table.Type {
 	return table.new_type(idx)
 }
 
-pub fn (p mut Parser) parse_multi_return_type() table.Type {
+pub fn (mut p Parser) parse_multi_return_type() table.Type {
 	p.check(.lpar)
-	var mr_types := []table.Type
+	mut mr_types := []table.Type
 	for {
 		mr_type := p.parse_type()
 		mr_types << mr_type
@@ -65,12 +65,12 @@ pub fn (p mut Parser) parse_multi_return_type() table.Type {
 }
 
 // given anon name based off signature when `name` is blank
-pub fn (p mut Parser) parse_fn_type(name string) table.Type {
+pub fn (mut p Parser) parse_fn_type(name string) table.Type {
 	// p.warn('parse fn')
 	p.check(.key_fn)
 	line_nr := p.tok.line_nr
 	args, is_variadic := p.fn_args()
-	var return_type := table.void_type
+	mut return_type := table.void_type
 	if p.tok.line_nr == line_nr && p.tok.kind.is_start_of_type() {
 		return_type = p.parse_type()
 	}
@@ -84,7 +84,7 @@ pub fn (p mut Parser) parse_fn_type(name string) table.Type {
 	return table.new_type(idx)
 }
 
-pub fn (p mut Parser) parse_type_with_mut(is_mut bool) table.Type {
+pub fn (mut p Parser) parse_type_with_mut(is_mut bool) table.Type {
 	typ := p.parse_type()
 	if is_mut {
 		return table.type_set_nr_muls(typ, 1)
@@ -92,14 +92,14 @@ pub fn (p mut Parser) parse_type_with_mut(is_mut bool) table.Type {
 	return typ
 }
 
-pub fn (p mut Parser) parse_type() table.Type {
+pub fn (mut p Parser) parse_type() table.Type {
 	// optional
-	var is_optional := false
+	mut is_optional := false
 	if p.tok.kind == .question {
 		p.next()
 		is_optional = true
 	}
-	var nr_muls := 0
+	mut nr_muls := 0
 	if p.tok.kind == .key_mut {
 		nr_muls++
 		p.next()
@@ -119,7 +119,7 @@ pub fn (p mut Parser) parse_type() table.Type {
 		p.next()
 		p.check(.dot)
 	}
-	var typ := p.parse_any_type(is_c, is_js, nr_muls > 0)
+	mut typ := p.parse_any_type(is_c, is_js, nr_muls > 0)
 	if is_optional {
 		typ = table.type_set(typ, .optional)
 	}
@@ -129,8 +129,8 @@ pub fn (p mut Parser) parse_type() table.Type {
 	return typ
 }
 
-pub fn (p mut Parser) parse_any_type(is_c, is_js, is_ptr bool) table.Type {
-	var name := p.tok.lit
+pub fn (mut p Parser) parse_any_type(is_c, is_js, is_ptr bool) table.Type {
+	mut name := p.tok.lit
 	if is_c {
 		name = 'C.$name'
 	} else if is_js {
@@ -229,7 +229,7 @@ pub fn (p mut Parser) parse_any_type(is_c, is_js, is_ptr bool) table.Type {
 				else {
 					// struct / enum / placeholder
 					// struct / enum
-					var idx := p.table.find_type_idx(name)
+					mut idx := p.table.find_type_idx(name)
 					if idx > 0 {
 						return table.new_type(idx)
 					}
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index 3c2aac986b..f4efc9cf16 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -233,7 +233,7 @@ pub fn (mut p Parser) parse_block_no_scope() []ast.Stmt {
 }
 
 /*
-fn (p mut Parser) next_with_comment() {
+fn (mut p Parser) next_with_comment() {
 	p.tok = p.peek_tok
 	p.peek_tok = p.scanner.scan()
 }
@@ -501,7 +501,7 @@ fn (mut p Parser) attribute() ast.Attr {
 }
 
 /*
-fn (p mut Parser) range_expr(low ast.Expr) ast.Expr {
+fn (mut p Parser) range_expr(low ast.Expr) ast.Expr {
 	// ,table.Type) {
 	if p.tok.kind != .dotdot {
 		p.next()
diff --git a/vlib/v/table/cflags.v b/vlib/v/table/cflags.v
index 389bf9bf83..dcc6a255a9 100644
--- a/vlib/v/table/cflags.v
+++ b/vlib/v/table/cflags.v
@@ -17,15 +17,15 @@ fn (table &Table) has_cflag(flag cflag.CFlag) bool {
 
 // parse the flags to (table.cflags) []CFlag
 // Note: clean up big time (joe-c)
-pub fn (var table Table) parse_cflag(cflg, mod string, ctimedefines []string) ?bool {
+pub fn (table mut Table) parse_cflag(cflg, mod string, ctimedefines []string) ?bool {
 	allowed_flags := ['framework', 'library', 'Wa', 'Wl', 'Wp', 'I', 'l', 'L']
 	flag_orig := cflg.trim_space()
-	var flag := flag_orig
+	mut flag := flag_orig
 	if flag == '' {
 		return none
 	}
-	var fos := ''
-	var allowed_os_overrides := ['linux', 'darwin', 'freebsd', 'windows', 'mingw', 'solaris']
+	mut fos := ''
+	mut allowed_os_overrides := ['linux', 'darwin', 'freebsd', 'windows', 'mingw', 'solaris']
 	allowed_os_overrides << ctimedefines
 	for os_override in allowed_os_overrides {
 		if !flag.starts_with(os_override) {
@@ -38,8 +38,8 @@ pub fn (var table Table) parse_cflag(cflg, mod string, ctimedefines []string) ?b
 		flag = flag[pos..].trim_space()
 	}
 	for {
-		var name := ''
-		var value := ''
+		mut name := ''
+		mut value := ''
 		if flag[0] == `-` {
 			for f in allowed_flags {
 				i := 1 + f.len
@@ -50,11 +50,11 @@ pub fn (var table Table) parse_cflag(cflg, mod string, ctimedefines []string) ?b
 				}
 			}
 		}
-		var index := flag.index(' -') or {
+		mut index := flag.index(' -') or {
 			-1
 		}
 		for index > -1 {
-			var has_next := false
+			mut has_next := false
 			for f in allowed_flags {
 				i := index + 2 + f.len
 				if i <= flag.len && f == flag[index + 2..i] {
diff --git a/vlib/v/table/table.v b/vlib/v/table/table.v
index 2dec05f7b9..b05b1ee5fa 100644
--- a/vlib/v/table/table.v
+++ b/vlib/v/table/table.v
@@ -45,14 +45,14 @@ mut:
 }
 
 pub fn new_table() &Table {
-	var t := &Table{}
+	mut t := &Table{}
 	t.register_builtin_type_symbols()
 	return t
 }
 
 // used to compare fn's & for naming anon fn's
 pub fn (f &Fn) signature() string {
-	var sig := ''
+	mut sig := ''
 	for i, arg in f.args {
 		// TODO: for now ignore mut/pts in sig for now
 		typ := type_set_nr_muls(arg.typ, 0)
@@ -85,12 +85,12 @@ pub fn (t &Table) known_fn(name string) bool {
 	return true
 }
 
-pub fn (var t Table) register_fn(new_fn Fn) {
+pub fn (mut t Table) register_fn(new_fn Fn) {
 	// println('reg fn $new_fn.name nr_args=$new_fn.args.len')
 	t.fns[new_fn.name] = new_fn
 }
 
-pub fn (var t TypeSymbol) register_method(new_fn Fn) {
+pub fn (mut t TypeSymbol) register_method(new_fn Fn) {
 	t.methods << new_fn
 }
 
@@ -142,7 +142,7 @@ pub fn (t &Table) type_has_method(s &TypeSymbol, name string) bool {
 // search from current type up through each parent looking for method
 pub fn (t &Table) type_find_method(s &TypeSymbol, name string) ?Fn {
 	// println('type_find_method($s.name, $name) types.len=$t.types.len s.parent_idx=$s.parent_idx')
-	var ts := s
+	mut ts := s
 	for {
 		if method := ts.find_method(name) {
 			return method
@@ -166,7 +166,7 @@ pub fn (t &Table) struct_has_field(s &TypeSymbol, name string) bool {
 // search from current type up through each parent looking for field
 pub fn (t &Table) struct_find_field(s &TypeSymbol, name string) ?Field {
 	// println('struct_find_field($s.name, $name) types.len=$t.types.len s.parent_idx=$s.parent_idx')
-	var ts := s
+	mut ts := s
 	for {
 		if field := ts.find_field(name) {
 			return field
@@ -214,7 +214,7 @@ pub fn (t &Table) get_type_name(typ Type) string {
 // allows prexisitng types added in register_builtins
 // to be overriden with their real type info
 [inline]
-pub fn (var t Table) register_builtin_type_symbol(typ TypeSymbol) int {
+pub fn (mut t Table) register_builtin_type_symbol(typ TypeSymbol) int {
 	existing_idx := t.type_idxs[typ.name]
 	if existing_idx > 0 {
 		if existing_idx >= string_type_idx {
@@ -234,7 +234,7 @@ pub fn (var t Table) register_builtin_type_symbol(typ TypeSymbol) int {
 }
 
 [inline]
-pub fn (var t Table) register_type_symbol(typ TypeSymbol) int {
+pub fn (mut t Table) register_type_symbol(typ TypeSymbol) int {
 	// println('register_type_symbol( $typ.name )')
 	existing_idx := t.type_idxs[typ.name]
 	if existing_idx > 0 {
@@ -308,7 +308,7 @@ pub fn (t &Table) map_name(key_type, value_type Type) string {
 	// return 'map_${value_type_sym.name}' + suffix
 }
 
-pub fn (var t Table) find_or_register_map(key_type, value_type Type) int {
+pub fn (mut t Table) find_or_register_map(key_type, value_type Type) int {
 	name := t.map_name(key_type, value_type)
 	// existing
 	existing_idx := t.type_idxs[name]
@@ -328,7 +328,7 @@ pub fn (var t Table) find_or_register_map(key_type, value_type Type) int {
 	return t.register_type_symbol(map_typ)
 }
 
-pub fn (var t Table) find_or_register_array(elem_type Type, nr_dims int) int {
+pub fn (mut t Table) find_or_register_array(elem_type Type, nr_dims int) int {
 	name := t.array_name(elem_type, nr_dims)
 	// existing
 	existing_idx := t.type_idxs[name]
@@ -348,7 +348,7 @@ pub fn (var t Table) find_or_register_array(elem_type Type, nr_dims int) int {
 	return t.register_type_symbol(array_type)
 }
 
-pub fn (var t Table) find_or_register_array_fixed(elem_type Type, size, nr_dims int) int {
+pub fn (mut t Table) find_or_register_array_fixed(elem_type Type, size, nr_dims int) int {
 	name := t.array_fixed_name(elem_type, size, nr_dims)
 	// existing
 	existing_idx := t.type_idxs[name]
@@ -368,8 +368,8 @@ pub fn (var t Table) find_or_register_array_fixed(elem_type Type, size, nr_dims
 	return t.register_type_symbol(array_fixed_type)
 }
 
-pub fn (var t Table) find_or_register_multi_return(mr_typs []Type) int {
-	var name := 'multi_return'
+pub fn (mut t Table) find_or_register_multi_return(mr_typs []Type) int {
+	mut name := 'multi_return'
 	for mr_typ in mr_typs {
 		mr_type_sym := t.get_type_symbol(mr_typ)
 		name += '_$mr_type_sym.name'
@@ -390,7 +390,7 @@ pub fn (var t Table) find_or_register_multi_return(mr_typs []Type) int {
 	return t.register_type_symbol(mr_type)
 }
 
-pub fn (var t Table) find_or_register_fn_type(f Fn, is_anon bool, has_decl bool) int {
+pub fn (mut t Table) find_or_register_fn_type(f Fn, is_anon bool, has_decl bool) int {
 	name := if f.name.len == 0 { 'anon_fn_$f.signature()' } else { f.name }
 	return t.register_type_symbol(TypeSymbol{
 		kind: .function
@@ -403,7 +403,7 @@ pub fn (var t Table) find_or_register_fn_type(f Fn, is_anon bool, has_decl bool)
 	})
 }
 
-pub fn (var t Table) add_placeholder_type(name string) int {
+pub fn (mut t Table) add_placeholder_type(name string) int {
 	ph_type := TypeSymbol{
 		kind: .placeholder
 		name: name
diff --git a/vlib/v/tests/match_test.v b/vlib/v/tests/match_test.v
index 370ed20caa..d8eabbae35 100644
--- a/vlib/v/tests/match_test.v
+++ b/vlib/v/tests/match_test.v
@@ -9,8 +9,8 @@ pub fn (c Color) str() string {
 }
 
 fn test_match_integers() {
-	var a := 3
-	var b := 0
+	mut a := 3
+	mut b := 0
 	match a {
 		2 { println('two') }
 		3 {
@@ -63,7 +63,7 @@ fn test_match_integers() {
 }
 
 fn test_match_enums() {
-	var b := Color.red
+	mut b := Color.red
 	match b {
 		.red { b = .green }
 		.green { b = .blue }