diff --git a/LICENSE b/LICENSE
index 24a4e4596..a9a41df13 100644
--- a/LICENSE
+++ b/LICENSE
@@ -20,3 +20,6 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 
+The source files 'gen_server2.erl' and 'priority_queue.erl' are from RabbitMQ
+v3.5.4 and licensed under MPL license.
+