diff --git a/util/proto/marshal.go b/util/proto/marshal.go
index 2d5f9e6..8570f6a 100644
--- a/util/proto/marshal.go
+++ b/util/proto/marshal.go
@@ -16,10 +16,10 @@ func BytesMarshal(field int, buf, v []byte) (int, error) {
 		return 0, nil
 	}
 
+	prefix := field<<3 | 0x2
+
 	// buf length check can prevent panic at PutUvarint, but it will make
 	// marshaller a bit slower.
-
-	prefix := field<<3 | 0x2
 	i := binary.PutUvarint(buf, uint64(prefix))
 	i += binary.PutUvarint(buf[i:], uint64(len(v)))
 	i += copy(buf[i:], v)
@@ -46,6 +46,30 @@ func StringSize(field int, v string) int {
 	return BytesSize(field, []byte(v))
 }
 
+func BoolMarshal(field int, buf []byte, v bool) (int, error) {
+	if !v {
+		return 0, nil
+	}
+
+	prefix := field << 3
+
+	// buf length check can prevent panic at PutUvarint, but it will make
+	// marshaller a bit slower.
+	i := binary.PutUvarint(buf, uint64(prefix))
+	buf[i] = 0x1
+
+	return i + 1, nil
+}
+
+func BoolSize(field int, v bool) int {
+	if !v {
+		return 0
+	}
+
+	prefix := field << 3
+	return VarUIntSize(uint64(prefix)) + 1 // bool is always 1 byte long
+}
+
 // varUIntSize returns length of varint byte sequence for uint64 value 'x'.
 func VarUIntSize(x uint64) int {
 	return (bits.Len64(x|1) + 6) / 7
diff --git a/util/proto/marshal_test.go b/util/proto/marshal_test.go
index 66a8b62..36847dd 100644
--- a/util/proto/marshal_test.go
+++ b/util/proto/marshal_test.go
@@ -12,6 +12,7 @@ import (
 type stablePrimitives struct {
 	FieldA []byte
 	FieldB string
+	FieldC bool
 }
 
 func (s *stablePrimitives) stableMarshal(buf []byte, wrongField bool) ([]byte, error) {
@@ -43,7 +44,17 @@ func (s *stablePrimitives) stableMarshal(buf []byte, wrongField bool) ([]byte, e
 	}
 	offset, err = proto.StringMarshal(fieldNum, buf, s.FieldB)
 	if err != nil {
-		return nil, errors.Wrap(err, "can't marshal field a")
+		return nil, errors.Wrap(err, "can't marshal field b")
+	}
+	i += offset
+
+	fieldNum = 200
+	if wrongField {
+		fieldNum++
+	}
+	offset, err = proto.BoolMarshal(fieldNum, buf, s.FieldC)
+	if err != nil {
+		return nil, errors.Wrap(err, "can't marshal field c")
 	}
 	i += offset
 
@@ -52,7 +63,8 @@ func (s *stablePrimitives) stableMarshal(buf []byte, wrongField bool) ([]byte, e
 
 func (s *stablePrimitives) stableSize() int {
 	return proto.BytesSize(1, s.FieldA) +
-		proto.StringSize(2, s.FieldB)
+		proto.StringSize(2, s.FieldB) +
+		proto.BoolSize(200, s.FieldC)
 }
 
 func TestBytesMarshal(t *testing.T) {
@@ -71,6 +83,29 @@ func TestBytesMarshal(t *testing.T) {
 	})
 }
 
+func TestStringMarshal(t *testing.T) {
+	t.Run("not empty", func(t *testing.T) {
+		data := "Hello World"
+		testStringMarshal(t, data, false)
+		testStringMarshal(t, data, true)
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		testStringMarshal(t, "", false)
+	})
+}
+
+func TestBoolMarshal(t *testing.T) {
+	t.Run("true", func(t *testing.T) {
+		testBoolMarshal(t, true, false)
+		testBoolMarshal(t, true, true)
+	})
+
+	t.Run("false", func(t *testing.T) {
+		testBoolMarshal(t, false, false)
+	})
+}
+
 func testBytesMarshal(t *testing.T, data []byte, wrongField bool) {
 	var (
 		wire []byte
@@ -107,18 +142,6 @@ func testBytesMarshal(t *testing.T, data []byte, wrongField bool) {
 	}
 }
 
-func TestStringMarshal(t *testing.T) {
-	t.Run("not empty", func(t *testing.T) {
-		data := "Hello World"
-		testStringMarshal(t, data, false)
-		testStringMarshal(t, data, true)
-	})
-
-	t.Run("empty", func(t *testing.T) {
-		testStringMarshal(t, "", false)
-	})
-}
-
 func testStringMarshal(t *testing.T, s string, wrongField bool) {
 	var (
 		wire []byte
@@ -154,3 +177,36 @@ func testStringMarshal(t *testing.T, s string, wrongField bool) {
 		require.Len(t, result.FieldB, 0)
 	}
 }
+
+func testBoolMarshal(t *testing.T, b bool, wrongField bool) {
+	var (
+		wire []byte
+		err  error
+
+		custom    = stablePrimitives{FieldC: b}
+		transport = test.Primitives{FieldC: b}
+	)
+
+	wire, err = custom.stableMarshal(nil, wrongField)
+	require.NoError(t, err)
+
+	wireGen, err := transport.Marshal()
+	require.NoError(t, err)
+
+	if !wrongField {
+		// we can check equality because single field cannot be unstable marshalled
+		require.Equal(t, wireGen, wire)
+	} else {
+		require.NotEqual(t, wireGen, wire)
+	}
+
+	result := new(test.Primitives)
+	err = result.Unmarshal(wire)
+	require.NoError(t, err)
+
+	if !wrongField {
+		require.Equal(t, b, result.FieldC)
+	} else {
+		require.False(t, false, result.FieldC)
+	}
+}
diff --git a/util/proto/test/test.pb.go b/util/proto/test/test.pb.go
index 9a1afd3..910812c 100644
Binary files a/util/proto/test/test.pb.go and b/util/proto/test/test.pb.go differ
diff --git a/util/proto/test/test.proto b/util/proto/test/test.proto
index 81a1058..4be07a4 100644
--- a/util/proto/test/test.proto
+++ b/util/proto/test/test.proto
@@ -3,6 +3,7 @@ syntax = "proto3";
 package test;
 
 message Primitives {
-    bytes field_a = 1;
+    bytes field_a  = 1;
     string field_b = 2;
+    bool field_c   = 200;
 }
\ No newline at end of file