diff --git a/vlib/builtin/map_test.v b/vlib/builtin/map_test.v
index e951680a5d..7bc77e9239 100644
--- a/vlib/builtin/map_test.v
+++ b/vlib/builtin/map_test.v
@@ -485,6 +485,8 @@ fn test_int_keys() {
 	m[5] += 24
 	m[5]++
 	assert m[5] == 25
+	m2 := {3:9 4:16 5:25}
+	assert m2.len == 3
 	mc := m.clone()
 	assert mc.len == 3
 	mut all := []int{}
@@ -506,6 +508,21 @@ fn test_voidptr_keys() {
 	assert m.len == 2
 }
 
+fn test_rune_keys() {
+	mut m := {`!`:2 `%`:3}
+	assert typeof(m).name == 'map[rune]int'
+	assert m[`!`] == 2
+	m[`@`] = 7
+	assert m.len == 3
+	
+	mut a := []rune{}
+	for k, v in m {
+		a << k
+		a << rune(v) + `0`
+	}
+	assert a == [`!`, `2`, `%`, `3`, `@`, `7`]
+}
+
 fn test_eq() {
 	a := {
 		'a': 1
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 9b92b25aaa..6b7f5b8755 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -4656,6 +4656,25 @@ pub fn (mut c Checker) chan_init(mut node ast.ChanInit) table.Type {
 	}
 }
 
+pub fn (mut c Checker) check_dup_keys(node &ast.MapInit, i int) {
+	key_i := node.keys[i]
+	if key_i is ast.StringLiteral {
+		for j in 0 .. i {
+			key_j := node.keys[j] as ast.StringLiteral
+			if key_i.val == key_j.val {
+				c.error('duplicate key "$key_i.val" in map literal', key_i.pos)
+			}
+		}
+	} else if key_i is ast.IntegerLiteral {
+		for j in 0 .. i {
+			key_j := node.keys[j] as ast.IntegerLiteral
+			if key_i.val == key_j.val {
+				c.error('duplicate key "$key_i.val" in map literal', key_i.pos)
+			}
+		}
+	}
+}
+
 pub fn (mut c Checker) map_init(mut node ast.MapInit) table.Type {
 	// `x := map[string]string` - set in parser
 	if node.typ != 0 {
@@ -4675,14 +4694,8 @@ pub fn (mut c Checker) map_init(mut node ast.MapInit) table.Type {
 	// `{'age': 20}`
 	key0_type := c.table.mktyp(c.expr(node.keys[0]))
 	val0_type := c.table.mktyp(c.expr(node.vals[0]))
+	mut same_key_type := true
 	for i, key in node.keys {
-		key_i := key as ast.StringLiteral
-		for j in 0 .. i {
-			key_j := node.keys[j] as ast.StringLiteral
-			if key_i.val == key_j.val {
-				c.error('duplicate key "$key_i.val" in map literal', key.position())
-			}
-		}
 		if i == 0 {
 			continue
 		}
@@ -4690,16 +4703,18 @@ pub fn (mut c Checker) map_init(mut node ast.MapInit) table.Type {
 		key_type := c.expr(key)
 		val_type := c.expr(val)
 		if !c.check_types(key_type, key0_type) {
-			key0_type_sym := c.table.get_type_symbol(key0_type)
-			key_type_sym := c.table.get_type_symbol(key_type)
-			c.error('map init: cannot use `$key_type_sym.name` as `$key0_type_sym.name` for map key',
-				node.pos)
+			msg := c.expected_msg(key_type, key0_type)
+			c.error('invalid map key: $msg', key.position())
+			same_key_type = false
 		}
 		if !c.check_types(val_type, val0_type) {
-			val0_type_sym := c.table.get_type_symbol(val0_type)
-			val_type_sym := c.table.get_type_symbol(val_type)
-			c.error('map init: cannot use `$val_type_sym.name` as `$val0_type_sym.name` for map value',
-				node.pos)
+			msg := c.expected_msg(val_type, val0_type)
+			c.error('invalid map value: $msg', val.position())
+		}
+	}
+	if same_key_type {
+		for i in 1 .. node.keys.len {
+			c.check_dup_keys(node, i)
 		}
 	}
 	map_type := table.new_type(c.table.find_or_register_map(key0_type, val0_type))
diff --git a/vlib/v/checker/tests/map_init_key_duplicate_err.out b/vlib/v/checker/tests/map_init_key_duplicate_err.out
index 975a814458..5798002c82 100644
--- a/vlib/v/checker/tests/map_init_key_duplicate_err.out
+++ b/vlib/v/checker/tests/map_init_key_duplicate_err.out
@@ -5,3 +5,9 @@ vlib/v/checker/tests/map_init_key_duplicate_err.vv:5:3: error: duplicate key "fo
       |         ~~~~~
     6 |     }
     7 |     println(a)
+vlib/v/checker/tests/map_init_key_duplicate_err.vv:9:15: error: duplicate key "2" in map literal
+    7 |     println(a)
+    8 |     
+    9 |     _ = {2:0 3:0 2:0}
+      |                  ^
+   10 | }
diff --git a/vlib/v/checker/tests/map_init_key_duplicate_err.vv b/vlib/v/checker/tests/map_init_key_duplicate_err.vv
index 497c61a46b..952c003726 100644
--- a/vlib/v/checker/tests/map_init_key_duplicate_err.vv
+++ b/vlib/v/checker/tests/map_init_key_duplicate_err.vv
@@ -5,4 +5,6 @@ fn main() {
 		'foo': 'bar'
 	}
 	println(a)
+	
+	_ = {2:0 3:0 2:0}
 }
diff --git a/vlib/v/checker/tests/map_init_wrong_type.out b/vlib/v/checker/tests/map_init_wrong_type.out
index c49ce4d904..c15c9fdcaf 100644
--- a/vlib/v/checker/tests/map_init_wrong_type.out
+++ b/vlib/v/checker/tests/map_init_wrong_type.out
@@ -3,4 +3,18 @@ vlib/v/checker/tests/map_init_wrong_type.vv:3:10: error: cannot assign to `a`: e
     2 |    mut a := map[string]f32{}
     3 |    a = { 'x': 12.3 }
       |          ~~~
-    4 | }
+    4 |    _ = {2:0 3:0 "hi":0}
+    5 |    _ = {2:0 3:`@` 4:0}
+vlib/v/checker/tests/map_init_wrong_type.vv:4:17: error: invalid map key: expected `int`, not `string`
+    2 |    mut a := map[string]f32{}
+    3 |    a = { 'x': 12.3 }
+    4 |    _ = {2:0 3:0 "hi":0}
+      |                 ~~~~
+    5 |    _ = {2:0 3:`@` 4:0}
+    6 | }
+vlib/v/checker/tests/map_init_wrong_type.vv:5:15: error: invalid map value: expected `int`, not `rune`
+    3 |    a = { 'x': 12.3 }
+    4 |    _ = {2:0 3:0 "hi":0}
+    5 |    _ = {2:0 3:`@` 4:0}
+      |               ~~~
+    6 | }
diff --git a/vlib/v/checker/tests/map_init_wrong_type.vv b/vlib/v/checker/tests/map_init_wrong_type.vv
index 273509d43d..fb77120b14 100644
--- a/vlib/v/checker/tests/map_init_wrong_type.vv
+++ b/vlib/v/checker/tests/map_init_wrong_type.vv
@@ -1,4 +1,6 @@
 fn main() {
    mut a := map[string]f32{}
    a = { 'x': 12.3 }
+   _ = {2:0 3:0 "hi":0}
+   _ = {2:0 3:`@` 4:0}
 }
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index b67b9c5a45..8d210c5b29 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -2302,7 +2302,7 @@ fn (mut g Gen) map_fn_ptrs(key_typ table.TypeSymbol) (string, string, string, st
 			key_eq_fn = '&map_eq_int_2'
 			clone_fn = '&map_clone_int_2'
 		}
-		.int, .u32 {
+		.int, .u32, .rune {
 			hash_fn = '&map_hash_int_4'
 			key_eq_fn = '&map_eq_int_4'
 			clone_fn = '&map_clone_int_4'
diff --git a/vlib/v/parser/containers.v b/vlib/v/parser/containers.v
index bdc3ffc331..20af0c877b 100644
--- a/vlib/v/parser/containers.v
+++ b/vlib/v/parser/containers.v
@@ -152,8 +152,10 @@ fn (mut p Parser) map_init() ast.MapInit {
 	mut keys := []ast.Expr{}
 	mut vals := []ast.Expr{}
 	for p.tok.kind != .rcbr && p.tok.kind != .eof {
-		// p.check(.str)
 		key := p.expr(0)
+		if key is ast.FloatLiteral {
+			p.error_with_pos('maps do not support floating point keys yet', key.pos)
+		}
 		keys << key
 		p.check(.colon)
 		val := p.expr(0)
diff --git a/vlib/v/parser/pratt.v b/vlib/v/parser/pratt.v
index c19ab55133..e8fed08b15 100644
--- a/vlib/v/parser/pratt.v
+++ b/vlib/v/parser/pratt.v
@@ -193,7 +193,7 @@ pub fn (mut p Parser) expr(precedence int) ast.Expr {
 		.lcbr {
 			// Map `{"age": 20}` or `{ x | foo:bar, a:10 }`
 			p.next()
-			if p.tok.kind == .string {
+			if p.tok.kind in [.chartoken, .number, .string] {
 				node = p.map_init()
 			} else {
 				// it should be a struct
diff --git a/vlib/v/token/token.v b/vlib/v/token/token.v
index 8bf8f4fadc..470e7d561e 100644
--- a/vlib/v/token/token.v
+++ b/vlib/v/token/token.v
@@ -21,7 +21,7 @@ pub enum Kind {
 	number // 123
 	string // 'foo'
 	str_inter // 'name=$user.name'
-	chartoken // `A`
+	chartoken // `A` - rune
 	plus
 	minus
 	mul