diff --git a/vlib/json/json_encode_enum_test.v b/vlib/json/json_encode_enum_test.v
new file mode 100644
index 0000000000..096be2b78e
--- /dev/null
+++ b/vlib/json/json_encode_enum_test.v
@@ -0,0 +1,134 @@
+import json
+
+[json_as_number]
+pub enum MessageType {
+	error = 1
+	warning = 2
+	info = 3
+	log = 4
+}
+
+pub enum MessageType2 {
+	error = 1
+	warning = 2
+	info = 3
+	log = 4
+}
+
+enum TestEnum {
+	one = 1
+	two
+}
+
+type TestAlias = TestEnum
+type TestSum = TestEnum | string
+type TestSum2 = MessageType | string
+type TestAliasAttr = MessageType
+
+struct TestStruct {
+	test  []TestEnum
+	test2 TestEnum
+	test3 TestAlias
+	test4 TestSum
+	test5 MessageType
+}
+
+struct TestStruct2 {
+	a TestAliasAttr
+	b TestSum2
+	c TestSum2
+}
+
+struct Test {
+	ab ?int
+	a  ?MessageType
+}
+
+struct Test2 {
+	a ?MessageType2
+}
+
+type TSum = MessageType | string
+type TSum2 = MessageType2 | string
+
+struct Test3 {
+	a ?TSum
+}
+
+struct Test4 {
+	a ?TSum2
+}
+
+fn test_encode_with_enum() {
+	out := json.encode(TestStruct{
+		test: [TestEnum.one, TestEnum.one]
+		test2: TestEnum.two
+		test3: TestEnum.one
+		test4: TestEnum.two
+		test5: .log
+	})
+	assert out == '{"test":["one","one"],"test2":"two","test3":"one","test4":"two","test5":4}'
+}
+
+fn test_encode_direct_enum() {
+	assert json.encode(TestEnum.one) == '"one"'
+}
+
+fn test_encode_alias_and_sumtype() {
+	assert json.decode(TestStruct, '{"test":["one","one"],"test2":"two","test3": "one", "test4": "two", "test5":4}')! == TestStruct{
+		test: [.one, .one]
+		test2: .two
+		test3: TestAlias(.one)
+		test4: TestSum('two')
+		test5: .log
+	}
+}
+
+fn test_enum_attr() {
+	assert dump(json.encode(MessageType.log)) == '4'
+	assert dump(json.encode(MessageType.error)) == '1'
+}
+
+fn test_enum_attr_decode() {
+	assert json.decode(TestStruct2, '{"a": 1, "b":4, "c": "test"}')! == TestStruct2{
+		a: .error
+		b: MessageType.log
+		c: 'test'
+	}
+}
+
+fn test_enum_attr_encode() {
+	assert json.encode(TestStruct2{
+		a: .error
+		b: MessageType.log
+		c: 'test'
+	}) == '{"a":1,"b":4,"c":"test"}'
+}
+
+fn test_option_enum() {
+	assert dump(json.encode(Test{none, none})) == '{}'
+	assert dump(json.encode(Test{none, MessageType.log})) == '{"a":4}'
+	t := dump(json.decode(Test, '{"a":4}')!)
+	assert t.ab == none
+	assert t.a? == .log
+
+	t2 := dump(json.decode(Test, '{"a":null}')!)
+	assert t2.a == none
+
+	assert json.encode(Test2{none}) == '{}'
+	assert dump(json.encode(Test2{MessageType2.log})) == '{"a":"log"}'
+	z := dump(json.decode(Test2, '{"a":"log"}')!)
+	assert z.a? == .log
+	a := dump(json.decode(Test2, '{"a": null}')!)
+	assert a.a == none
+}
+
+fn test_option_sumtype_enum() {
+	assert dump(json.encode(Test3{none})) == '{}'
+	assert dump(json.encode(Test3{ a: 'foo' })) == '{"a":"foo"}'
+	assert dump(json.encode(Test3{ a: MessageType.warning })) == '{"a":2}'
+
+	assert dump(json.encode(Test4{none})) == '{}'
+	assert dump(json.encode(Test4{ a: 'foo' })) == '{"a":"foo"}'
+	assert dump(json.encode(Test4{ a: MessageType2.warning })) == '{"a":"warning"}'
+}
diff --git a/vlib/json/json_test.v b/vlib/json/json_test.v
index 8de3f9c289..f745091b2b 100644
--- a/vlib/json/json_test.v
+++ b/vlib/json/json_test.v
@@ -18,7 +18,7 @@ fn test_simple() {
 	x := Employee{'Peter', 28, 95000.5, .worker}
 	s := json.encode(x)
 	// eprintln('Employee x: $s')
-	assert s == '{"name":"Peter","age":28,"salary":95000.5,"title":2}'
+	assert s == '{"name":"Peter","age":28,"salary":95000.5,"title":"worker"}'
 	y := json.decode(Employee, s)!
 	// eprintln('Employee y: $y')
 	assert y.name == 'Peter'
@@ -95,14 +95,15 @@ fn test_encode_decode_sumtype() {
 	enc := json.encode(game)
 	// eprintln('Encoded Game: $enc')
 
-	assert enc == '{"title":"Super Mega Game","player":{"name":"Monke","_type":"Human"},"other":[{"tag":"Pen","_type":"Item"},{"tag":"Cookie","_type":"Item"},1,"Stool",{"_type":"Time","value":${t.unix_time()}}]}'
+	assert enc == '{"title":"Super Mega Game","player":{"name":"Monke","_type":"Human"},"other":[{"tag":"Pen","_type":"Item"},{"tag":"Cookie","_type":"Item"},"cat","Stool",{"_type":"Time","value":${t.unix_time()}}]}'
 
 	dec := json.decode(SomeGame, enc)!
 	// eprintln('Decoded Game: $dec')
 
 	assert game.title == dec.title
 	assert game.player == dec.player
-	assert (game.other[2] as Animal) == (dec.other[2] as Animal)
+	assert (game.other[2] as Animal) == .cat
+	assert dec.other[2] == Entity('cat')
 	assert (game.other[4] as time.Time).unix_time() == (dec.other[4] as time.Time).unix_time()
 }
 
diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index 602822d10c..f999dd7a70 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -6144,16 +6144,21 @@ fn (mut g Gen) size_of(node ast.SizeOf) {
 	g.write('sizeof(${util.no_dots(styp)})')
 }
 
-fn (mut g Gen) enum_val(node ast.EnumVal) {
-	styp := g.typ(g.table.unaliased_type(node.typ))
-	if g.pref.translated && node.typ.is_number() {
+[inline]
+fn (mut g Gen) gen_enum_prefix(typ ast.Type) string {
+	if g.pref.translated && typ.is_number() {
 		// Mostly in translated code, when C enums are used as ints in switches
-		g.write('_const_main__${node.val}')
+		return '_const_main__'
 	} else {
-		g.write('${styp}__${node.val}')
+		styp := g.typ(g.table.unaliased_type(typ))
+		return '${styp}__'
 	}
 }
 
+fn (mut g Gen) enum_val(node ast.EnumVal) {
+	g.write('${g.gen_enum_prefix(node.typ)}${node.val}')
+}
+
 fn (mut g Gen) as_cast(node ast.AsCast) {
 	// Make sure the sum type can be cast to this type (the types
 	// are the same), otherwise panic.
diff --git a/vlib/v/gen/c/json.v b/vlib/v/gen/c/json.v
index b481601ec4..57d463c336 100644
--- a/vlib/v/gen/c/json.v
+++ b/vlib/v/gen/c/json.v
@@ -26,7 +26,7 @@ import strings
 fn (mut g Gen) gen_json_for_type(typ ast.Type) {
 	utyp := g.unwrap_generic(typ)
 	sym := g.table.sym(utyp)
-	if (is_js_prim(sym.name) && !utyp.has_flag(.option)) || sym.kind == .enum_ {
+	if is_js_prim(sym.name) && !utyp.has_flag(.option) {
 		return
 	}
 	g.json_types << utyp
@@ -145,9 +145,11 @@ ${enc_fn_dec} {
 				g.gen_json_for_type(parent_typ)
 				continue
 			}
-			enc.writeln('\to = cJSON_CreateObject();')
 			if psym.info is ast.Struct {
+				enc.writeln('\to = cJSON_CreateObject();')
 				g.gen_struct_enc_dec(utyp, psym.info, ret_styp, mut enc, mut dec)
+			} else if psym.kind == .enum_ {
+				g.gen_enum_enc_dec(utyp, psym, mut enc, mut dec)
 			} else if psym.kind == .sum_type {
 				verror('json: ${sym.name} aliased sumtypes does not work at the moment')
 			} else {
@@ -160,6 +162,8 @@ ${enc_fn_dec} {
 				verror('json: ${sym.name} is not a sumtype')
 			}
 			g.gen_sumtype_enc_dec(utyp, sym, mut enc, mut dec, ret_styp)
+		} else if sym.kind == .enum_ {
+			g.gen_enum_enc_dec(utyp, sym, mut enc, mut dec)
 		} else if utyp.has_flag(.option) && sym.info !is ast.Struct {
 			g.gen_option_enc_dec(utyp, mut enc, mut dec)
 		} else {
@@ -183,6 +187,73 @@ ${enc_fn_dec} {
 	}
 }
 
+[inline]
+fn (mut g Gen) gen_enum_to_str(utyp ast.Type, sym ast.TypeSymbol, enum_var string, result_var string, ident string, mut enc strings.Builder) {
+	enum_prefix := g.gen_enum_prefix(utyp.clear_flag(.option))
+	enc.writeln('${ident}switch (${enum_var}) {')
+	for val in (sym.info as ast.Enum).vals {
+		enc.write_string('${ident}\tcase ${enum_prefix}${val}:\t')
+		enc.writeln('${result_var} = json__encode_string(_SLIT("${val}")); break;')
+	}
+	enc.writeln('${ident}}')
+}
+
+[inline]
+fn (mut g Gen) gen_str_to_enum(utyp ast.Type, sym ast.TypeSymbol, val_var string, result_var string, ident string, mut dec strings.Builder) {
+	enum_prefix := g.gen_enum_prefix(utyp.clear_flag(.option))
+	is_option := utyp.has_flag(.option)
+	for k, val in (sym.info as ast.Enum).vals {
+		if k == 0 {
+			dec.write_string('${ident}if (string__eq(_SLIT("${val}"), ${val_var}))\t')
+		} else {
+			dec.write_string('${ident}else if (string__eq(_SLIT("${val}"), ${val_var}))\t')
+		}
+		if is_option {
+			base_typ := g.base_type(utyp)
+			dec.writeln('_option_ok(&(${base_typ}[]){ ${enum_prefix}${val} }, ${result_var}, sizeof(${base_typ}));')
+		} else {
+			dec.writeln('${result_var} = ${enum_prefix}${val};')
+		}
+	}
+}
+
+[inline]
+fn (mut g Gen) is_enum_as_int(sym ast.TypeSymbol) bool {
+	if enum_decl := g.table.enum_decls[sym.name] {
+		if _ := enum_decl.attrs.find_first('json_as_number') {
+			return true
+		}
+	}
+	return false
+}
+
+[inline]
+fn (mut g Gen) gen_enum_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc strings.Builder, mut dec strings.Builder) {
+	is_option := utyp.has_flag(.option)
+
+	if g.is_enum_as_int(sym) {
+		if is_option {
+			base_typ := g.typ(utyp.clear_flag(.option))
+			enc.writeln('\to = ${js_enc_name('u64')}(*val.data);')
+			dec.writeln('\t_option_ok(&(${base_typ}[]){ ${js_dec_name('u64')}(root) }, &res, sizeof(${base_typ}));')
+		} else {
+			dec.writeln('\tres = ${js_dec_name('u64')}(root);')
+			enc.writeln('\to = ${js_enc_name('u64')}(val);')
+		}
+	} else {
+		tmp := g.new_tmp_var()
+		dec.writeln('\tstring ${tmp} = ${js_dec_name('string')}(root);')
+		if is_option {
+			g.gen_str_to_enum(utyp, sym, tmp, '&res', '\t', mut dec)
+			g.gen_enum_to_str(utyp, sym, '*(${g.base_type(utyp)}*)val.data', 'o', '\t\t', mut
+				enc)
+		} else {
+			g.gen_str_to_enum(utyp, sym, tmp, 'res', '\t', mut dec)
+			g.gen_enum_to_str(utyp, sym, 'val', 'o', '\t', mut enc)
+		}
+	}
+}
+
 [inline]
 fn (mut g Gen) gen_option_enc_dec(typ ast.Type, mut enc strings.Builder, mut dec strings.Builder) {
 	enc.writeln('\tif (val.state == 2) {')
@@ -191,6 +262,9 @@ fn (mut g Gen) gen_option_enc_dec(typ ast.Type, mut enc strings.Builder, mut dec
 	type_str := g.typ(typ.clear_flag(.option))
 	encode_name := js_enc_name(type_str)
 	enc.writeln('\to = ${encode_name}(*(${type_str}*)val.data);')
+
+	dec_name := js_dec_name(type_str)
+	dec.writeln('\t_option_ok(&(${type_str}[]){ ${dec_name}(root) }, &res, sizeof(${type_str}));')
 }
 
 [inline]
@@ -200,6 +274,8 @@ fn (mut g Gen) gen_sumtype_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc st
 	typ := g.table.type_idxs[sym.name]
 	prefix := if utyp.is_ptr() { '*' } else { '' }
 	field_op := if utyp.is_ptr() { '->' } else { '.' }
+	is_option := utyp.has_flag(.option)
+	var_data := if is_option { '(*(${g.base_type(utyp)}*)val.data)' } else { 'val' }
 
 	// DECODING (inline)
 	$if !json_no_inline_sumtypes ? {
@@ -231,20 +307,38 @@ fn (mut g Gen) gen_sumtype_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc st
 		g.definitions.writeln('static inline ${sym.cname} ${variant_typ}_to_sumtype_${sym.cname}(${variant_typ}* x);')
 
 		// ENCODING
-		enc.writeln('\tif (val${field_op}_typ == ${variant.idx()}) {')
+		if is_option {
+			enc.writeln('\tif (${var_data}${field_op}_typ == ${variant.idx()}) {')
+		} else {
+			enc.writeln('\tif (val${field_op}_typ == ${variant.idx()}) {')
+		}
 		$if json_no_inline_sumtypes ? {
 			if variant_sym.kind == .enum_ {
-				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name('u64')}(*val${field_op}_${variant_typ}));')
+				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name('u64')}(*${var_data}${field_op}_${variant_typ}));')
 			} else if variant_sym.name == 'time.Time' {
-				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name('i64')}(val${field_op}_${variant_typ}->_v_unix));')
+				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name('i64')}(${var_data}${field_op}_${variant_typ}->_v_unix));')
 			} else {
-				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name(variant_typ)}(*val${field_op}_${variant_typ}));')
+				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name(variant_typ)}(*${var_data}${field_op}_${variant_typ}));')
 			}
 		} $else {
 			if is_js_prim(variant_typ) {
-				enc.writeln('\t\to = ${js_enc_name(variant_typ)}(*val${field_op}_${variant_typ});')
+				enc.writeln('\t\tcJSON_free(o); return ${js_enc_name(variant_typ)}(*${var_data}${field_op}_${variant_typ});')
 			} else if variant_sym.kind == .enum_ {
-				enc.writeln('\t\to = ${js_enc_name('u64')}(*val${field_op}_${variant_typ});')
+				if g.is_enum_as_int(variant_sym) {
+					enc.writeln('\t\tcJSON_free(o); return ${js_enc_name('u64')}(*${var_data}${field_op}_${variant_typ});')
+				} else {
+					enc.writeln('\t\tcJSON_free(o);')
+					tmp2 := g.new_tmp_var()
+					if utyp.has_flag(.option) {
+						enc.writeln('\t\tu64 ${tmp2} = *${var_data}${field_op}_${variant_typ};')
+						g.gen_enum_to_str(variant, variant_sym, tmp2, 'o', '\t\t', mut
+							enc)
+					} else {
+						enc.writeln('\t\tu64 ${tmp2} = *${var_data}${field_op}_${variant_typ};')
+						g.gen_enum_to_str(variant, variant_sym, tmp2, 'o', '\t\t', mut
+							enc)
+					}
+				}
 			} else if variant_sym.name == 'time.Time' {
 				enc.writeln('\t\tcJSON_AddItemToObject(o, "_type", cJSON_CreateString("${unmangled_variant_name}"));')
 				enc.writeln('\t\tcJSON_AddItemToObject(o, "value", ${js_enc_name('i64')}(val${field_op}_${variant_typ}->_v_unix));')
@@ -260,25 +354,38 @@ fn (mut g Gen) gen_sumtype_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc st
 		$if json_no_inline_sumtypes ? {
 			dec.writeln('\tif (strcmp("${unmangled_variant_name}", root->child->string) == 0) {')
 			if is_js_prim(variant_typ) {
-				gen_js_get(variant_typ, tmp, unmangled_variant_name, mut dec, true)
+				gen_js_get(ret_styp, tmp, unmangled_variant_name, mut dec, true)
 				dec.writeln('\t\t${variant_typ} value = ${js_dec_name(variant_typ)}(jsonroot_${tmp});')
 			} else if variant_sym.kind == .enum_ {
-				gen_js_get(variant_typ, tmp, unmangled_variant_name, mut dec, true)
-				dec.writeln('\t\t${variant_typ} value = ${js_dec_name('u64')}(jsonroot_${tmp});')
+				if g.is_enum_as_int(variant_sym) {
+					gen_js_get(ret_styp, tmp, unmangled_variant_name, mut dec, true)
+					dec.writeln('\t\t${variant_typ} value = ${js_dec_name('u64')}(jsonroot_${tmp});')
+				} else {
+					gen_js_get(ret_styp, tmp, unmangled_variant_name, mut dec, true)
+					dec.writeln('\t\t${variant_typ} value;')
+					tmp2 := g.new_tmp_var()
+					dec.writeln('\t\tstring ${tmp2} = json__decode_string(jsonroot_${tmp});')
+					g.gen_enum_to_str(variant, variant_sym, tmp2, 'value', '\t\t', mut
+						dec)
+				}
 			} else if variant_sym.name == 'time.Time' {
-				gen_js_get(variant_typ, tmp, unmangled_variant_name, mut dec, true)
+				gen_js_get(ret_styp, tmp, unmangled_variant_name, mut dec, true)
 				dec.writeln('\t\t${variant_typ} value = time__unix(${js_dec_name('i64')}(jsonroot_${tmp}));')
 			} else {
-				gen_js_get_opt(js_dec_name(variant_typ), variant_typ, sym.cname, tmp,
-					unmangled_variant_name, mut dec, true)
+				gen_js_get_opt(js_dec_name(variant_typ), variant_typ, ret_styp, tmp, unmangled_variant_name, mut
+					dec, true)
 				dec.writeln('\t\t${variant_typ} value = *(${variant_typ}*)(${tmp}.data);')
 			}
-			dec.writeln('\t\tres = ${variant_typ}_to_sumtype_${sym.cname}(&value);')
+			if is_option {
+				dec.writeln('\t\t\t_option_ok(&(${sym.cname}[]){ ${variant_typ}_to_sumtype_${sym.cname}(&value) }, &res, sizeof(${sym.cname}));')
+			} else {
+				dec.writeln('\t\tres = ${variant_typ}_to_sumtype_${ret_styp}(&value);')
+			}
 			dec.writeln('\t}')
 		} $else {
 			if variant_sym.name == 'time.Time' {
 				dec.writeln('\t\t\tif (strcmp("Time", ${type_var}) == 0) {')
-				gen_js_get(sym.cname, tmp, 'value', mut dec, true)
+				gen_js_get(ret_styp, tmp, 'value', mut dec, true)
 				dec.writeln('\t\t\t\t${variant_typ} ${tmp} = time__unix(${js_dec_name('i64')}(jsonroot_${tmp}));')
 				dec.writeln('\t\t\t\t${prefix}res = ${variant_typ}_to_sumtype_${sym.cname}(&${tmp});')
 				dec.writeln('\t\t\t}')
@@ -325,7 +432,11 @@ fn (mut g Gen) gen_sumtype_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc st
 					last_number_type = var_t
 					dec.writeln('\t\tif (cJSON_IsNumber(root)) {')
 					dec.writeln('\t\t\t${var_t} value = ${js_dec_name('u64')}(root);')
-					dec.writeln('\t\t\t${prefix}res = ${var_t}_to_sumtype_${sym.cname}(&value);')
+					if utyp.has_flag(.option) {
+						dec.writeln('\t\t\t_option_ok(&(${sym.cname}[]){ ${var_t}_to_sumtype_${sym.cname}(&value) }, &${prefix}res, sizeof(${sym.cname}));')
+					} else {
+						dec.writeln('\t\t\t${prefix}res = ${var_t}_to_sumtype_${sym.cname}(&value);')
+					}
 					dec.writeln('\t\t}')
 				}
 
@@ -337,7 +448,11 @@ fn (mut g Gen) gen_sumtype_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc st
 					string_is_met = true
 					dec.writeln('\t\tif (cJSON_IsString(root)) {')
 					dec.writeln('\t\t\t${var_t} value = ${js_dec_name(var_t)}(root);')
-					dec.writeln('\t\t\t${prefix}res = ${var_t}_to_sumtype_${sym.cname}(&value);')
+					if utyp.has_flag(.option) {
+						dec.writeln('\t\t\t_option_ok(&(${sym.cname}[]){ ${var_t}_to_sumtype_${sym.cname}(&value) }, &${prefix}res, sizeof(${sym.cname}));')
+					} else {
+						dec.writeln('\t\t\t${prefix}res = ${var_t}_to_sumtype_${sym.cname}(&value);')
+					}
 					dec.writeln('\t\t}')
 				}
 
@@ -437,12 +552,36 @@ fn (mut g Gen) gen_struct_enc_dec(utyp ast.Type, type_info ast.TypeInfo, styp st
 				dec.writeln('\t}')
 			} else if field_sym.kind == .enum_ {
 				tmp := g.new_tmp_var()
-				gen_js_get(styp, tmp, name, mut dec, is_required)
-				dec.writeln('\tif (jsonroot_${tmp}) {')
-				dec.writeln('\t\t${prefix}${op}${c_name(field.name)} = json__decode_u64(jsonroot_${tmp});')
+				is_option_field := field.typ.has_flag(.option)
+				if field.typ.has_flag(.option) {
+					gen_js_get_opt(js_dec_name(field_type), field_type, styp, tmp, name, mut
+						dec, true)
+					dec.writeln('\tif (jsonroot_${tmp} && !cJSON_IsNull(jsonroot_${tmp})) {')
+				} else {
+					gen_js_get(styp, tmp, name, mut dec, is_required)
+					dec.writeln('\tif (jsonroot_${tmp}) {')
+				}
+				if g.is_enum_as_int(field_sym) {
+					if is_option_field {
+						base_typ := g.base_type(field.typ)
+						dec.writeln('\t\t_option_ok(&(${base_typ}[]) { ${js_dec_name('u64')}(jsonroot_${tmp}) }, &${prefix}${op}${c_name(field.name)}, sizeof(${base_typ}));')
+					} else {
+						dec.writeln('\t\t${prefix}${op}${c_name(field.name)} = ${js_dec_name('u64')}(jsonroot_${tmp});')
+					}
+				} else {
+					if is_option_field {
+						base_typ := g.base_type(field.typ)
+						dec.writeln('\t\t_option_ok(&(${base_typ}[]) { *(${base_typ}*)((${g.typ(field.typ)}*)${tmp}.data)->data }, &${prefix}${op}${c_name(field.name)}, sizeof(${base_typ}));')
+					} else {
+						tmp2 := g.new_tmp_var()
+						dec.writeln('\t\tstring ${tmp2} = json__decode_string(jsonroot_${tmp});')
+						g.gen_str_to_enum(field.typ, field_sym, tmp2, '${prefix}${op}${c_name(field.name)}',
+							'\t\t', mut dec)
+					}
+				}
 				if field.has_default_expr {
 					dec.writeln('\t} else {')
-					dec.writeln('\t\t${prefix}.${c_name(field.name)} = ${g.expr_string(field.default_expr)};')
+					dec.writeln('\t\t${prefix}${op}${c_name(field.name)} = ${g.expr_string(field.default_expr)};')
 				}
 				dec.writeln('\t}')
 			} else if field_sym.name == 'time.Time' {
@@ -507,8 +646,9 @@ fn (mut g Gen) gen_struct_enc_dec(utyp ast.Type, type_info ast.TypeInfo, styp st
 		} else {
 			'val'
 		}
-		if field.typ.has_flag(.option) {
-			enc.writeln('\tif (val${op}${c_name(field.name)}.state != 2)')
+		is_option := field.typ.has_flag(.option)
+		if is_option {
+			enc.writeln('\tif (val${op}${c_name(field.name)}.state != 2) {')
 		}
 		if is_omit_empty {
 			enc.writeln('\t if (val${op}${c_name(field.name)} != ${g.type_default(field.typ)})')
@@ -520,7 +660,29 @@ fn (mut g Gen) gen_struct_enc_dec(utyp ast.Type, type_info ast.TypeInfo, styp st
 			}
 		}
 		if field_sym.kind == .enum_ {
-			enc.writeln('\tcJSON_AddItemToObject(o, "${name}", json__encode_u64(${prefix_enc}${op}${c_name(field.name)}));\n')
+			if g.is_enum_as_int(field_sym) {
+				if field.typ.has_flag(.option) {
+					enc.writeln('\tcJSON_AddItemToObject(o, "${name}", json__encode_u64(*${prefix_enc}${op}${c_name(field.name)}.data));\n')
+				} else {
+					enc.writeln('\tcJSON_AddItemToObject(o, "${name}", json__encode_u64(${prefix_enc}${op}${c_name(field.name)}));\n')
+				}
+			} else {
+				if field.typ.has_flag(.option) {
+					enc.writeln('\t{')
+					enc.writeln('\t\tcJSON *enum_val;')
+					g.gen_enum_to_str(field.typ, field_sym, '*(${g.base_type(field.typ)}*)${prefix_enc}${op}${c_name(field.name)}.data',
+						'enum_val', '\t\t', mut enc)
+					enc.writeln('\t\tcJSON_AddItemToObject(o, "${name}", enum_val);')
+					enc.writeln('\t}')
+				} else {
+					enc.writeln('\t{')
+					enc.writeln('\t\tcJSON *enum_val;')
+					g.gen_enum_to_str(field.typ, field_sym, '${prefix_enc}${op}${c_name(field.name)}',
+						'enum_val', '\t\t', mut enc)
+					enc.writeln('\t\tcJSON_AddItemToObject(o, "${name}", enum_val);')
+					enc.writeln('\t}')
+				}
+			}
 		} else {
 			if field_sym.name == 'time.Time' {
 				// time struct requires special treatment
@@ -542,6 +704,10 @@ fn (mut g Gen) gen_struct_enc_dec(utyp ast.Type, type_info ast.TypeInfo, styp st
 				}
 			}
 		}
+
+		if is_option {
+			enc.writeln('\t} // !none')
+		}
 	}
 }
 
@@ -557,7 +723,7 @@ fn gen_js_get(styp string, tmp string, name string, mut dec strings.Builder, is_
 fn gen_js_get_opt(dec_name string, field_type string, styp string, tmp string, name string, mut dec strings.Builder, is_required bool) {
 	gen_js_get(styp, tmp, name, mut dec, is_required)
 	value_field_type := field_type.replace('*', '_ptr')
-	dec.writeln('\t${result_name}_${value_field_type.replace('*', '_ptr')} ${tmp};')
+	dec.writeln('\t${result_name}_${value_field_type.replace('*', '_ptr')} ${tmp} = {0};')
 	dec.writeln('\tif (jsonroot_${tmp}) {')
 	dec.writeln('\t\t${tmp} = ${dec_name}(jsonroot_${tmp});')
 	dec.writeln('\t\tif (${tmp}.is_error) {')