diff --git a/xs/src/libslic3r/GCodeTimeEstimator.hpp b/xs/src/libslic3r/GCodeTimeEstimator.hpp
index 9e429462e8..63dd0a6c6f 100644
--- a/xs/src/libslic3r/GCodeTimeEstimator.hpp
+++ b/xs/src/libslic3r/GCodeTimeEstimator.hpp
@@ -7,6 +7,11 @@
 
 namespace Slic3r {
 
+    //
+    // Some of the algorithms used by class GCodeTimeEstimator were inpired by
+    // Cura Engine's class TimeEstimateCalculator
+    // https://github.com/Ultimaker/CuraEngine/blob/master/src/timeEstimate.h
+    //
     class GCodeTimeEstimator
     {
     public: