diff --git a/counter_sample.go b/counter_sample.go
index 31df19b..2b5084f 100644
--- a/counter_sample.go
+++ b/counter_sample.go
@@ -48,7 +48,7 @@ func (s *CounterSample) GetRecords() []Record {
 	return s.Records
 }
 
-func decodeCounterSample(r io.ReadSeeker) (Sample, error) {
+func decodeCounterSample(r io.ReadSeeker, format uint32) (Sample, error) {
 	s := &CounterSample{}
 
 	var err error
@@ -58,24 +58,43 @@ func decodeCounterSample(r io.ReadSeeker) (Sample, error) {
 		return nil, err
 	}
 
-	err = binary.Read(r, binary.BigEndian, &s.SourceIdType)
-	if err != nil {
-		return nil, err
-	}
+	switch format {
+	case TypeCounterSample:
+		err = binary.Read(r, binary.BigEndian, &s.SourceIdType)
+		if err != nil {
+			return nil, err
+		}
 
-	var srcIdIndexVal [3]byte
-	n, err := r.Read(srcIdIndexVal[:])
-	if err != nil {
-		return nil, err
-	}
+		var srcIdIndexVal [3]byte
+		n, err := r.Read(srcIdIndexVal[:])
+		if err != nil {
+			return nil, err
+		}
 
-	if n != 3 {
-		return nil, errors.New("sflow: counter sample decoding error")
-	}
+		if n != 3 {
+			return nil, errors.New("sflow: counter sample decoding error")
+		}
+
+		s.SourceIdIndexVal = uint32(srcIdIndexVal[2]) |
+			uint32(srcIdIndexVal[1])<<8 |
+			uint32(srcIdIndexVal[0])<<16
+
+	case TypeExpandedCounterSample:
+		var sourceIdType uint32
+		err = binary.Read(r, binary.BigEndian, &sourceIdType)
+		if err != nil {
+			return nil, err
+		}
+		s.SourceIdType = byte(sourceIdType)
+
+		err = binary.Read(r, binary.BigEndian, &s.SourceIdIndexVal)
+		if err != nil {
+			return nil, err
+		}
 
-	s.SourceIdIndexVal = uint32(srcIdIndexVal[2]) |
-		uint32(srcIdIndexVal[1])<<8 |
-		uint32(srcIdIndexVal[0])<<16
+	default:
+		return nil, ErrUnknownSampleType
+	}
 
 	err = binary.Read(r, binary.BigEndian, &s.numRecords)
 	if err != nil {
diff --git a/counter_sample_encode_test.go b/counter_sample_encode_test.go
index 6befa51..5d42bed 100644
--- a/counter_sample_encode_test.go
+++ b/counter_sample_encode_test.go
@@ -48,7 +48,7 @@ func TestDecodeEncodeAndDecodeCounterSample(t *testing.T) {
 	buf.Read(skip[:])
 
 	// bytes.Buffer is not an io.ReadSeeker. bytes.Reader is.
-	decodedSample, err := decodeCounterSample(bytes.NewReader(buf.Bytes()))
+	decodedSample, err := decodeCounterSample(bytes.NewReader(buf.Bytes()), TypeCounterSample)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/sample.go b/sample.go
index 140b788..d425fb0 100644
--- a/sample.go
+++ b/sample.go
@@ -39,7 +39,10 @@ func decodeSample(r io.ReadSeeker) (Sample, error) {
 
 	switch format {
 	case TypeCounterSample:
-		return decodeCounterSample(r)
+		return decodeCounterSample(r, format)
+
+	case TypeExpandedCounterSample:
+		return decodeCounterSample(r, format)
 
 	case TypeFlowSample:
 		return decodeFlowSample(r)