diff --git a/cartographer_ros/cartographer_ros/rosbag_validate_main.cc b/cartographer_ros/cartographer_ros/rosbag_validate_main.cc
index b05db39..6cc282e 100644
--- a/cartographer_ros/cartographer_ros/rosbag_validate_main.cc
+++ b/cartographer_ros/cartographer_ros/rosbag_validate_main.cc
@@ -311,13 +311,13 @@ void Run(const std::string& bag_filename, const bool dump_timing) {
     auto& entry = frame_id_to_properties.at(frame_id);
     if (!first_packet) {
       const double delta_t_sec = (time - entry.last_timestamp).toSec();
-      if (delta_t_sec < 0) {
+      if (delta_t_sec <= 0) {
         LOG_FIRST_N(ERROR, 3)
             << "Sensor with frame_id \"" << frame_id
-            << "\" jumps backwards in time. Make sure that the bag "
-               "contains the data for each frame_id sorted by "
-               "header.stamp, i.e. the order in which they were "
-               "acquired from the sensor.";
+            << "\" jumps backwards in time, i.e. timestamps are not strictly "
+               "increasing. Make sure that the bag contains the data for each "
+               "frame_id sorted by header.stamp, i.e. the order in which they "
+               "were acquired from the sensor.";
       }
       entry.time_deltas.push_back(delta_t_sec);
     }