diff --git a/src/image/jpeg/reader.go b/src/image/jpeg/reader.go
index 2c3c2f72f8..435b67a020 100644
--- a/src/image/jpeg/reader.go
+++ b/src/image/jpeg/reader.go
@@ -170,7 +170,7 @@ func (d *decoder) fill() error {
 // can happen when expecting to read a 0xff 0x00 byte-stuffed byte.
 func (d *decoder) unreadByteStuffedByte() {
 	if d.bytes.nUnreadable == 0 {
-		panic("jpeg: unreadByteStuffedByte call cannot be fulfilled")
+		return
 	}
 	d.bytes.i -= d.bytes.nUnreadable
 	d.bytes.nUnreadable = 0
@@ -242,12 +242,7 @@ func (d *decoder) readByteStuffedByte() (x byte, err error) {
 // stuffing.
 func (d *decoder) readFull(p []byte) error {
 	// Unread the overshot bytes, if any.
-	if d.bytes.nUnreadable != 0 {
-		if d.bits.n >= 8 {
-			d.unreadByteStuffedByte()
-		}
-		d.bytes.nUnreadable = 0
-	}
+	d.unreadByteStuffedByte()
 
 	for {
 		n := copy(p, d.bytes.buf[d.bytes.i:d.bytes.j])
@@ -269,12 +264,7 @@ func (d *decoder) readFull(p []byte) error {
 // ignore ignores the next n bytes.
 func (d *decoder) ignore(n int) error {
 	// Unread the overshot bytes, if any.
-	if d.bytes.nUnreadable != 0 {
-		if d.bits.n >= 8 {
-			d.unreadByteStuffedByte()
-		}
-		d.bytes.nUnreadable = 0
-	}
+	d.unreadByteStuffedByte()
 
 	for {
 		m := d.bytes.j - d.bytes.i
diff --git a/src/image/jpeg/reader_test.go b/src/image/jpeg/reader_test.go
index c5a36cba21..5964b92aac 100644
--- a/src/image/jpeg/reader_test.go
+++ b/src/image/jpeg/reader_test.go
@@ -186,6 +186,26 @@ func pixString(pix []byte, stride, x, y int) string {
 	return s.String()
 }
 
+func TestTruncatedSOSDataDoesntPanic(t *testing.T) {
+	b, err := ioutil.ReadFile("../testdata/video-005.gray.q50.jpeg")
+	if err != nil {
+		t.Fatal(err)
+	}
+	sosMarker := []byte{0xff, 0xda}
+	i := bytes.Index(b, sosMarker)
+	if i < 0 {
+		t.Fatal("SOS marker not found")
+	}
+	i += len(sosMarker)
+	j := i + 10
+	if j > len(b) {
+		j = len(b)
+	}
+	for ; i < j; i++ {
+		Decode(bytes.NewReader(b[:i]))
+	}
+}
+
 func TestExtraneousData(t *testing.T) {
 	// Encode a 1x1 red image.
 	src := image.NewRGBA(image.Rect(0, 0, 1, 1))