diff --git a/src/structure/dds_cache.rs b/src/structure/dds_cache.rs
index c6e7379a..041c73bb 100644
--- a/src/structure/dds_cache.rs
+++ b/src/structure/dds_cache.rs
@@ -288,6 +288,18 @@ impl TopicCache {
     start_instant: Timestamp,
     end_instant: Timestamp,
   ) -> Box<dyn Iterator<Item = (Timestamp, &CacheChange)> + '_> {
+    // Sanity check
+    let start_instant = 
+      if start_instant <= end_instant { 
+        // sane case
+        start_instant 
+      } else {
+        // insane case
+        error!("get_changes_in_range_best_effort: Did my clock jump backwards? start={start_instant:?} end={end_instant:?}");
+        end_instant
+      };
+
+    // Get result as tree range
     Box::new(
       self
         .changes