diff --git a/util/proto/marshal.go b/util/proto/marshal.go
index a602b78..21e8013 100644
--- a/util/proto/marshal.go
+++ b/util/proto/marshal.go
@@ -384,3 +384,34 @@ func Float64Size(fNum int, v float64) int {
 
 	return VarUIntSize(uint64(prefix)) + 8
 }
+
+// Fixed32Marshal encodes uint32 value to Protocol Buffers fixed32 field with specified number,
+// and writes it to specified buffer. Returns number of bytes written.
+//
+// Panics if the buffer is undersized.
+func Fixed32Marshal(field int, buf []byte, v uint32) int {
+	if v == 0 {
+		return 0
+	}
+
+	prefix := field<<3 | 5
+
+	// buf length check can prevent panic at PutUvarint, but it will make
+	// marshaller a bit slower.
+	i := binary.PutUvarint(buf, uint64(prefix))
+	binary.LittleEndian.PutUint32(buf[i:], v)
+
+	return i + 4
+}
+
+// Fixed32Size returns number of bytes required to encode uint32 value to Protocol Buffers fixed32 field
+// with specified number.
+func Fixed32Size(fNum int, v uint32) int {
+	if v == 0 {
+		return 0
+	}
+
+	prefix := fNum<<3 | 5
+
+	return VarUIntSize(uint64(prefix)) + 4
+}
diff --git a/util/proto/marshal_test.go b/util/proto/marshal_test.go
index ba78c00..a3f6882 100644
--- a/util/proto/marshal_test.go
+++ b/util/proto/marshal_test.go
@@ -24,6 +24,7 @@ type stablePrimitives struct {
 	FieldH SomeEnum
 	FieldI uint64 // fixed64
 	FieldJ float64
+	FieldK uint32 // fixed32
 }
 
 type stableRepPrimitives struct {
@@ -144,6 +145,15 @@ func (s *stablePrimitives) stableMarshal(buf []byte, wrongField bool) ([]byte, e
 	}
 	i += offset
 
+	fieldNum = 207
+	if wrongField {
+		fieldNum++
+	}
+
+	offset = proto.Fixed32Marshal(fieldNum, buf, s.FieldK)
+
+	i += offset
+
 	fieldNum = 300
 	if wrongField {
 		fieldNum++
@@ -167,6 +177,7 @@ func (s *stablePrimitives) stableSize() int {
 		proto.UInt64Size(204, s.FieldG) +
 		proto.Fixed64Size(205, s.FieldI) +
 		proto.Float64Size(206, s.FieldJ) +
+		proto.Fixed32Size(207, s.FieldK) +
 		proto.EnumSize(300, int32(s.FieldH))
 }
 
@@ -478,6 +489,17 @@ func TestFloat64Marshal(t *testing.T) {
 	})
 }
 
+func TestFixed32Marshal(t *testing.T) {
+	t.Run("zero", func(t *testing.T) {
+		testFixed32Marshal(t, 0, false)
+	})
+
+	t.Run("non zero", func(t *testing.T) {
+		testFixed32Marshal(t, math.MaxUint32, false)
+		testFixed32Marshal(t, math.MaxUint32, true)
+	})
+}
+
 func testMarshal(t *testing.T, c stablePrimitives, tr test.Primitives, wrongField bool) *test.Primitives {
 	var (
 		wire []byte
@@ -791,3 +813,18 @@ func testFixed64Marshal(t *testing.T, n uint64, wrongField bool) {
 		require.EqualValues(t, 0, result.FieldI)
 	}
 }
+
+func testFixed32Marshal(t *testing.T, n uint32, wrongField bool) {
+	var (
+		custom    = stablePrimitives{FieldK: n}
+		transport = test.Primitives{FieldK: n}
+	)
+
+	result := testMarshal(t, custom, transport, wrongField)
+
+	if !wrongField {
+		require.Equal(t, n, result.FieldK)
+	} else {
+		require.EqualValues(t, 0, result.FieldK)
+	}
+}
diff --git a/util/proto/test/test.pb.go b/util/proto/test/test.pb.go
index 7ce722a..2a433a2 100644
Binary files a/util/proto/test/test.pb.go and b/util/proto/test/test.pb.go differ