decoder_test.go | 32 ++++++++++++++++++++++++++++++++
 encoder_test.go | 23 +++++++++++++++++++++++
 opus_test.go    | 61 -----------------------------------------------------
 utils_test.go   | 25 +++++++++++++++++++++++++

diff --git a/decoder_test.go b/decoder_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..e17883f3fee0ed3cb86dd0e4a59a468f861aa7ee
--- /dev/null
+++ b/decoder_test.go
@@ -0,0 +1,32 @@
+// Copyright © 2015, 2016 Hraban Luyat <hraban@0brg.net>
+//
+// License for use of this code is detailed in the LICENSE file
+
+package opus
+
+import (
+	"testing"
+)
+
+func TestDecoderNew(t *testing.T) {
+	dec, err := NewDecoder(48000, 1)
+	if err != nil || dec == nil {
+		t.Errorf("Error creating new decoder: %v", err)
+	}
+	dec, err = NewDecoder(12345, 1)
+	if err == nil || dec != nil {
+		t.Errorf("Expected error for illegal samplerate 12345")
+	}
+}
+
+func TestDecoderUnitialized(t *testing.T) {
+	var dec Decoder
+	_, err := dec.Decode(nil, nil)
+	if err != errDecUninitialized {
+		t.Errorf("Expected \"unitialized decoder\" error: %v", err)
+	}
+	_, err = dec.DecodeFloat32(nil, nil)
+	if err != errDecUninitialized {
+		t.Errorf("Expected \"unitialized decoder\" error: %v", err)
+	}
+}
diff --git a/encoder_test.go b/encoder_test.go
index b37489f8c6e15d34a6cf21276cbfd9e527910e38..527a5e3e127ab99004acc89494b2eefffe56e0af 100644
--- a/encoder_test.go
+++ b/encoder_test.go
@@ -6,6 +6,29 @@ package opus
 
 import "testing"
 
+func TestEncoderNew(t *testing.T) {
+	enc, err := NewEncoder(48000, 1, APPLICATION_VOIP)
+	if err != nil || enc == nil {
+		t.Errorf("Error creating new encoder: %v", err)
+	}
+	enc, err = NewEncoder(12345, 1, APPLICATION_VOIP)
+	if err == nil || enc != nil {
+		t.Errorf("Expected error for illegal samplerate 12345")
+	}
+}
+
+func TestEncoderUnitialized(t *testing.T) {
+	var enc Encoder
+	_, err := enc.Encode(nil, nil)
+	if err != errEncUninitialized {
+		t.Errorf("Expected \"unitialized encoder\" error: %v", err)
+	}
+	_, err = enc.EncodeFloat32(nil, nil)
+	if err != errEncUninitialized {
+		t.Errorf("Expected \"unitialized encoder\" error: %v", err)
+	}
+}
+
 func TestEncoderDTX(t *testing.T) {
 	enc, err := NewEncoder(8000, 1, APPLICATION_VOIP)
 	if err != nil || enc == nil {
diff --git a/opus_test.go b/opus_test.go
index 230f4265e78f7de866173dd7a8efc33650fa2500..fc91c2c69a5e769c9cbf5827dc5fbc3a7edcae24 100644
--- a/opus_test.go
+++ b/opus_test.go
@@ -5,7 +5,6 @@
 package opus
 
 import (
-	"math"
 	"strings"
 	"testing"
 )
@@ -16,52 +15,6 @@ 		t.Errorf("Unexpected linked libopus version: " + ver)
 	}
 }
 
-func TestEncoderNew(t *testing.T) {
-	enc, err := NewEncoder(48000, 1, APPLICATION_VOIP)
-	if err != nil || enc == nil {
-		t.Errorf("Error creating new encoder: %v", err)
-	}
-	enc, err = NewEncoder(12345, 1, APPLICATION_VOIP)
-	if err == nil || enc != nil {
-		t.Errorf("Expected error for illegal samplerate 12345")
-	}
-}
-
-func TestDecoderNew(t *testing.T) {
-	dec, err := NewDecoder(48000, 1)
-	if err != nil || dec == nil {
-		t.Errorf("Error creating new decoder: %v", err)
-	}
-	dec, err = NewDecoder(12345, 1)
-	if err == nil || dec != nil {
-		t.Errorf("Expected error for illegal samplerate 12345")
-	}
-}
-
-func TestEncoderUnitialized(t *testing.T) {
-	var enc Encoder
-	_, err := enc.Encode(nil, nil)
-	if err != errEncUninitialized {
-		t.Errorf("Expected \"unitialized encoder\" error: %v", err)
-	}
-	_, err = enc.EncodeFloat32(nil, nil)
-	if err != errEncUninitialized {
-		t.Errorf("Expected \"unitialized encoder\" error: %v", err)
-	}
-}
-
-func TestDecoderUnitialized(t *testing.T) {
-	var dec Decoder
-	_, err := dec.Decode(nil, nil)
-	if err != errDecUninitialized {
-		t.Errorf("Expected \"unitialized decoder\" error: %v", err)
-	}
-	_, err = dec.DecodeFloat32(nil, nil)
-	if err != errDecUninitialized {
-		t.Errorf("Expected \"unitialized decoder\" error: %v", err)
-	}
-}
-
 func TestOpusErrstr(t *testing.T) {
 	// I scooped this -1 up from opus_defines.h, it's OPUS_BAD_ARG. Not pretty,
 	// but it's better than not testing at all. Again, accessing #defines from
@@ -69,20 +22,6 @@ 	// CGO is not possible.
 	if ERR_OPUS_BAD_ARG.Error() != "opus: invalid argument" {
 		t.Errorf("Expected \"invalid argument\" error message for error code %d: %v",
 			ERR_OPUS_BAD_ARG, ERR_OPUS_BAD_ARG)
-	}
-}
-
-func addSineFloat32(buf []float32, sampleRate int, freq float64) {
-	factor := 2 * math.Pi * freq / float64(sampleRate)
-	for i := range buf {
-		buf[i] += float32(math.Sin(float64(i) * factor))
-	}
-}
-
-func addSine(buf []int16, sampleRate int, freq float64) {
-	factor := 2 * math.Pi * freq / float64(sampleRate)
-	for i := range buf {
-		buf[i] += int16(math.Sin(float64(i)*factor) * math.MaxInt16)
 	}
 }
 
diff --git a/utils_test.go b/utils_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..849db921aba3d1de55bfb8059d3b1e53bbe861c1
--- /dev/null
+++ b/utils_test.go
@@ -0,0 +1,25 @@
+// Copyright © 2015, 2016 Hraban Luyat <hraban@0brg.net>
+//
+// License for use of this code is detailed in the LICENSE file
+
+package opus
+
+import (
+	"math"
+)
+
+// utility functions for unit tests
+
+func addSineFloat32(buf []float32, sampleRate int, freq float64) {
+	factor := 2 * math.Pi * freq / float64(sampleRate)
+	for i := range buf {
+		buf[i] += float32(math.Sin(float64(i) * factor))
+	}
+}
+
+func addSine(buf []int16, sampleRate int, freq float64) {
+	factor := 2 * math.Pi * freq / float64(sampleRate)
+	for i := range buf {
+		buf[i] += int16(math.Sin(float64(i)*factor) * math.MaxInt16)
+	}
+}