diff --git a/LICENSE b/LICENSE
index 13b61daa..f1b456e9 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2018 Gabriel Vasile
+Copyright (c) 2018, 2019 Gabriel Vasile
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/matchers/signature.go b/matchers/signature.go
index 29daacb1..a3364de4 100644
--- a/matchers/signature.go
+++ b/matchers/signature.go
@@ -111,7 +111,7 @@ func (xSig xmlSig) detect(in []byte) bool {
 	}
 
 	localNameIndex := bytes.Index(in, xSig.localName)
-	return 0 < localNameIndex && localNameIndex < bytes.Index(in, xSig.xmlns)
+	return localNameIndex != -1 && localNameIndex < bytes.Index(in, xSig.xmlns)
 }
 
 func detect(in []byte, sigs []sig) bool {
diff --git a/matchers/video.go b/matchers/video.go
index bae9ea3f..694104b2 100644
--- a/matchers/video.go
+++ b/matchers/video.go
@@ -56,13 +56,6 @@ func Mpeg(in []byte) bool {
 		in[3] >= 0xB0 && in[3] <= 0xBF
 }
 
-// QuickTime matches a QuickTime File Format file.
-func QuickTime(in []byte) bool {
-	return len(in) > 12 &&
-		(bytes.Equal(in[4:12], []byte("ftypqt  ")) ||
-			bytes.Equal(in[4:8], []byte("moov")))
-}
-
 // Avi matches an Audio Video Interleaved file.
 func Avi(in []byte) bool {
 	return len(in) > 16 &&
diff --git a/matchers/video_ftyp.go b/matchers/video_ftyp.go
index 3fc35a87..2bb1d82c 100644
--- a/matchers/video_ftyp.go
+++ b/matchers/video_ftyp.go
@@ -28,6 +28,8 @@ var (
 		// Nero Digital AAC Audio
 		ftypSig("NDAS"),
 	}
+	qtSigs  = []sig{ftypSig("qt  "), ftypSig("moov")}
+	mqvSigs = []sig{ftypSig("mqt ")}
 	m4aSigs = []sig{ftypSig("M4A ")}
 	// TODO: add support for remaining video formats at ftyps.com
 )
@@ -37,22 +39,32 @@ func Mp4(in []byte) bool {
 	return detect(in, mp4Sigs)
 }
 
+// ThreeGP matches a 3GPP file.
+func ThreeGP(in []byte) bool {
+	return detect(in, threeGPSigs)
+}
+
+// ThreeG2 matches a 3GPP2 file.
+func ThreeG2(in []byte) bool {
+	return detect(in, threeG2Sigs)
+}
+
 // AMp4 matches an audio MP4 file.
 func AMp4(in []byte) bool {
 	return detect(in, amp4Sigs)
 }
 
-// M4a matches an audio M4A file.
-func M4a(in []byte) bool {
-	return detect(in, m4aSigs)
+// QuickTime matches a QuickTime File Format file.
+func QuickTime(in []byte) bool {
+	return detect(in, qtSigs)
 }
 
-// ThreeGP matches a 3GPP file.
-func ThreeGP(in []byte) bool {
-	return detect(in, threeGPSigs)
+// Mqv matches a Sony / Mobile QuickTime  file.
+func Mqv(in []byte) bool {
+	return detect(in, mqvSigs)
 }
 
-// ThreeG2 matches a 3GPP2 file.
-func ThreeG2(in []byte) bool {
-	return detect(in, threeG2Sigs)
+// M4a matches an audio M4A file.
+func M4a(in []byte) bool {
+	return detect(in, m4aSigs)
 }
diff --git a/mime_test.go b/mime_test.go
index d1145d4e..9cc59982 100644
--- a/mime_test.go
+++ b/mime_test.go
@@ -48,6 +48,7 @@ var files = map[string]*Node{
 	"a.flv":  Flv,
 	"a.avi":  Avi,
 	"a.mov":  QuickTime,
+	"a.mqv":  Mqv,
 	"a.mpeg": Mpeg,
 	"a.mkv":  Mkv,
 
diff --git a/node.go b/node.go
index 50f61463..1de058b2 100644
--- a/node.go
+++ b/node.go
@@ -72,8 +72,8 @@ func (n *Node) Tree() string {
 	return printTree(n, 0)
 }
 
-func (n *Node) flatten() (out []*Node) {
-	out = append(out, n)
+func (n *Node) flatten() []*Node {
+	out := []*Node{n}
 	for _, c := range n.children {
 		out = append(out, c.flatten()...)
 	}
diff --git a/supported_mimes.md b/supported_mimes.md
index 8c03ad49..34b0b072 100644
--- a/supported_mimes.md
+++ b/supported_mimes.md
@@ -38,6 +38,7 @@ Extension | MIME type
 **au** | audio/basic
 **mpeg** | video/mpeg
 **mov** | video/quicktime
+**mqv** | video/quicktime
 **mp4** | video/mp4
 **webm** | video/webm
 **3gp** | video/3gpp
diff --git a/testdata/a.mqv b/testdata/a.mqv
new file mode 100644
index 00000000..272a5c8d
Binary files /dev/null and b/testdata/a.mqv differ
diff --git a/tree.go b/tree.go
index b6f401ab..bcf346ea 100644
--- a/tree.go
+++ b/tree.go
@@ -9,7 +9,7 @@ var Root = NewNode("application/octet-stream", "", matchers.True,
 	SevenZ, Zip, Tar, Pdf, Doc, Xls, Ppt, Ps, Psd, Ogg,
 	Png, Jpg, Gif, Webp, Tiff, Bmp, Ico,
 	Mp3, Flac, Midi, Ape, MusePack, Amr, Wav, Aiff, Au,
-	Mpeg, QuickTime, Mp4, WebM, ThreeGP, ThreeG2, Avi, Flv, Mkv, AMp4, M4a,
+	Mpeg, QuickTime, Mqv, Mp4, WebM, ThreeGP, ThreeG2, Avi, Flv, Mkv, AMp4, M4a,
 	Txt, Gzip, Class, Swf, Crx, Woff, Woff2, Wasm,
 )
 
@@ -80,6 +80,7 @@ var (
 	WebM      = NewNode("video/webm", "webm", matchers.WebM)
 	Mpeg      = NewNode("video/mpeg", "mpeg", matchers.Mpeg)
 	QuickTime = NewNode("video/quicktime", "mov", matchers.QuickTime)
+	Mqv       = NewNode("video/quicktime", "mqv", matchers.Mqv)
 	ThreeGP   = NewNode("video/3gpp", "3gp", matchers.ThreeGP)
 	ThreeG2   = NewNode("video/3gpp2", "3g2", matchers.ThreeG2)
 	Avi       = NewNode("video/x-msvideo", "avi", matchers.Avi)