diff --git a/program/rust/src/tests/test_upd_price.rs b/program/rust/src/tests/test_upd_price.rs
index d370030f..54198511 100644
--- a/program/rust/src/tests/test_upd_price.rs
+++ b/program/rust/src/tests/test_upd_price.rs
@@ -93,7 +93,7 @@ fn test_upd_price() {
         assert_eq!(price_data.price_cumulative.num_down_slots, 0);
     }
 
-    // add some prices for current slot - get rejected
+    // a publisher's component pub_slot_ has to be strictly increasing -- get rejected
     populate_instruction(&mut instruction_data, 43, 2, 1);
 
     assert_eq!(
diff --git a/program/rust/src/tests/test_upd_price_no_fail_on_error.rs b/program/rust/src/tests/test_upd_price_no_fail_on_error.rs
index 1d175d8b..daf8d715 100644
--- a/program/rust/src/tests/test_upd_price_no_fail_on_error.rs
+++ b/program/rust/src/tests/test_upd_price_no_fail_on_error.rs
@@ -123,7 +123,7 @@ fn test_upd_price_no_fail_on_error_no_fail_on_error() {
         assert_eq!(price_data.agg_.status_, PC_STATUS_TRADING);
     }
 
-    // Invalid updates, such as publishing an update for the current slot,
+    // Invalid updates, such as publishing a price update with a pub_slot_ that's lower or equal than one that's already been published (by the same publisher),
     // should still fail silently and have no effect.
 
     // Check that the normal upd_price fails