diff --git a/vendor/github.com/pierrec/lz4/debug.go b/vendor/github.com/pierrec/lz4/debug.go
new file mode 100644
index 0000000..bc5e78d
--- /dev/null
+++ b/vendor/github.com/pierrec/lz4/debug.go
@@ -0,0 +1,23 @@
+// +build lz4debug
+
+package lz4
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+)
+
+const debugFlag = true
+
+func debug(args ...interface{}) {
+	_, file, line, _ := runtime.Caller(1)
+	file = filepath.Base(file)
+
+	f := fmt.Sprintf("LZ4: %s:%d %s", file, line, args[0])
+	if f[len(f)-1] != '\n' {
+		f += "\n"
+	}
+	fmt.Fprintf(os.Stderr, f, args[1:]...)
+}