diff --git a/fixtures/test.jp2 b/fixtures/test.jp2
new file mode 100644
index 0000000..940778f
Binary files /dev/null and b/fixtures/test.jp2 differ
diff --git a/type_test.go b/type_test.go
index e33f1f9..e769f53 100644
--- a/type_test.go
+++ b/type_test.go
@@ -18,6 +18,7 @@ func TestDeterminateImageType(t *testing.T) {
 		{"test.gif", GIF},
 		{"test.pdf", PDF},
 		{"test.svg", SVG},
+		{"test.jp2", MAGICK},
 	}
 
 	for _, file := range files {
@@ -42,6 +43,7 @@ func TestDeterminateImageTypeName(t *testing.T) {
 		{"test.gif", "gif"},
 		{"test.pdf", "pdf"},
 		{"test.svg", "svg"},
+		{"test.jp2", "magick"},
 	}
 
 	for _, file := range files {
diff --git a/vips.go b/vips.go
index cbf2304..0553170 100644
--- a/vips.go
+++ b/vips.go
@@ -531,7 +531,6 @@ func readImageType(buf []byte) string {
 	length := C.size_t(len(buf))
 	imageBuf := unsafe.Pointer(&buf[0])
 	load := C.vips_foreign_find_load_buffer(imageBuf, length)
-	defer C.free(imageBuf)
 	return C.GoString(load)
 }