diff --git a/internal/tlcodegen/type_rw.go b/internal/tlcodegen/type_rw.go
index 9428806c..753c86cc 100644
--- a/internal/tlcodegen/type_rw.go
+++ b/internal/tlcodegen/type_rw.go
@@ -907,6 +907,10 @@ func addAsterisk(ref bool, val string) string {
 	return ifString(ref, "*"+val, val)
 }
 
+func addAsteriskAndBrackets(ref bool, val string) string {
+	return ifString(ref, "(*"+val+")", val)
+}
+
 func wrapLast(last bool, code string) string {
 	return ifString(last, "return "+code+"", "if err := "+code+"; err != nil { return err }")
 }
diff --git a/internal/tlcodegen/type_rw_maybe_cpp.go b/internal/tlcodegen/type_rw_maybe_cpp.go
index 28cb3f37..bff8d2a2 100644
--- a/internal/tlcodegen/type_rw_maybe_cpp.go
+++ b/internal/tlcodegen/type_rw_maybe_cpp.go
@@ -142,7 +142,7 @@ bool %[6]s::%[1]sWriteBoxed(::basictl::tl_ostream & s, const %[2]s& item%[3]s) {
 			func() string {
 				indent := 1
 				s := ""
-				emptyCondition := trw.element.t.trw.CPPTypeJSONEmptyCondition(bytesVersion, "*item", false, nil)
+				emptyCondition := trw.element.t.trw.CPPTypeJSONEmptyCondition(bytesVersion, "(*item)", false, nil)
 				if emptyCondition != "" {
 					s += fmt.Sprintf("\tif(%s) {\n\t", emptyCondition)
 					indent = 2
diff --git a/internal/tlcodegen/type_rw_primitive_cpp.go b/internal/tlcodegen/type_rw_primitive_cpp.go
index 0c41ffc7..e13d1e3d 100644
--- a/internal/tlcodegen/type_rw_primitive_cpp.go
+++ b/internal/tlcodegen/type_rw_primitive_cpp.go
@@ -13,7 +13,7 @@ import (
 
 func (trw *TypeRWPrimitive) CPPTypeJSONEmptyCondition(bytesVersion bool, val string, ref bool, deps []string) string {
 	if trw.tlType == "string" {
-		return fmt.Sprintf("%s.size() != 0", addAsterisk(ref, val))
+		return fmt.Sprintf("%s.size() != 0", addAsteriskAndBrackets(ref, val))
 	}
 	return fmt.Sprintf("%s != 0", addAsterisk(ref, val))
 }
diff --git a/internal/tlcodegen/type_rw_struct_cpp.go b/internal/tlcodegen/type_rw_struct_cpp.go
index 1ca973b6..b720b18e 100644
--- a/internal/tlcodegen/type_rw_struct_cpp.go
+++ b/internal/tlcodegen/type_rw_struct_cpp.go
@@ -504,6 +504,18 @@ func (trw *TypeRWStruct) CPPWriteFields(bytesVersion bool) string {
 	return s.String()
 }
 
+func countFields(fields []Field) (count int) {
+	for _, field := range fields {
+		if field.t.IsTrueType() {
+			if field.fieldMask == nil || !(field.fieldMask.isField || field.fieldMask.isArith) {
+				continue
+			}
+		}
+		count++
+	}
+	return
+}
+
 func (trw *TypeRWStruct) CPPWriteJsonFields(bytesVersion bool) string {
 	var s strings.Builder
 	if trw.isTypeDef() {
@@ -517,8 +529,12 @@ func (trw *TypeRWStruct) CPPWriteJsonFields(bytesVersion bool) string {
 		return "	s << \"true\";\n"
 	}
 
-	s.WriteString(`	auto add_comma = false;
-	s << "{";
+	fieldsCount := countFields(trw.Fields)
+	if fieldsCount > 1 {
+		s.WriteString(`	auto add_comma = false;
+`)
+	}
+	s.WriteString(`	s << "{";
 `)
 	for i, field := range trw.Fields {
 		if field.t.IsTrueType() {
@@ -545,8 +561,10 @@ func (trw *TypeRWStruct) CPPWriteJsonFields(bytesVersion bool) string {
 				strings.Repeat("\t", indent+1),
 			))
 		}
-		s.WriteString(strings.Repeat("\t", indent+1))
-		s.WriteString("add_comma = true;\n")
+		if fieldsCount > 1 {
+			s.WriteString(strings.Repeat("\t", indent+1))
+			s.WriteString("add_comma = true;\n")
+		}
 		s.WriteString(fmt.Sprintf(`%ss << "\"%s\":";
 `,
 			strings.Repeat("\t", indent+1),
diff --git a/internal/tlcodegen/type_rw_tuple_cpp.go b/internal/tlcodegen/type_rw_tuple_cpp.go
index 2fe49595..2d5502dd 100644
--- a/internal/tlcodegen/type_rw_tuple_cpp.go
+++ b/internal/tlcodegen/type_rw_tuple_cpp.go
@@ -13,10 +13,10 @@ import (
 
 func (trw *TypeRWBrackets) CPPTypeJSONEmptyCondition(bytesVersion bool, val string, ref bool, deps []string) string {
 	if trw.dictLike || trw.vectorLike || trw.dynamicSize {
-		if trw.dynamicSize {
-			return fmt.Sprintf("(%s.size() != 0) || (%s != 0)", addAsterisk(ref, val), deps[0])
+		if trw.dynamicSize && len(deps) != 0 {
+			return fmt.Sprintf("(%s.size() != 0) || (%s != 0)", addAsteriskAndBrackets(ref, val), deps[0])
 		}
-		return fmt.Sprintf("%s.size() != 0", addAsterisk(ref, val))
+		return fmt.Sprintf("%s.size() != 0", addAsteriskAndBrackets(ref, val))
 	}
 	return ""
 }