diff --git a/lib/pure/mersenne.nim b/lib/pure/mersenne.nim
index afa343086c..36b597767a 100644
--- a/lib/pure/mersenne.nim
+++ b/lib/pure/mersenne.nim
@@ -1,3 +1,12 @@
+#
+#
+#            Nim's Runtime Library
+#        (c) Copyright 2015 Nim Contributors
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
 type
   MersenneTwister* = object
     mt: array[0..623, uint32]