diff --git a/src/global_timestamp_reader.cpp b/src/global_timestamp_reader.cpp
index 706c4d5c96..41ff1f2df8 100644
--- a/src/global_timestamp_reader.cpp
+++ b/src/global_timestamp_reader.cpp
@@ -145,7 +145,7 @@ namespace librealsense
             sample._x -= base_x;
         }
         _prev_time -= base_x;
-        _base_sample._y += a * base_x;
+        _base_sample._x -= base_x;
         return true;
     }