diff --git a/os/rt/src/chevents.c b/os/rt/src/chevents.c
index 0f41699cf..3286c5f94 100644
--- a/os/rt/src/chevents.c
+++ b/os/rt/src/chevents.c
@@ -333,7 +333,7 @@ void chEvtBroadcastFlags(event_source_t *esp, eventflags_t flags) {
 }
 
 /**
- * @brief   Returns the flags associated to an @p event_listener_t.
+ * @brief   Returns the unmasked flags associated to an @p event_listener_t.
  * @details The flags are returned and the @p event_listener_t flags mask is
  *          cleared.
  *
@@ -349,7 +349,7 @@ eventflags_t chEvtGetAndClearFlagsI(event_listener_t *elp) {
   flags = elp->flags;
   elp->flags = (eventflags_t)0;
 
-  return flags;
+  return flags & elp->wflags;
 }
 
 /**
diff --git a/readme.txt b/readme.txt
index e2cdcce56..031071bc4 100644
--- a/readme.txt
+++ b/readme.txt
@@ -141,6 +141,8 @@
 - EX:  Updated LIS302DL to 1.1.0 (backported to 18.2.1).
 - EX:  Updated LPS25H to 1.1.0 (backported to 18.2.1).
 - EX:  Updated LSM303DLHC to 1.1.0 (backported to 18.2.1).
+- RT:  Fixed chEvtGetAndClearFlags(...) does not mask events (bug #977)
+       (backported to 18.2.2 and 17.6.5).
 - HAL: Fixed HAL channels chnControl() macro broken (bug #976)
        (backported to 18.2.2).
 - OTH: Fixed wrong timeout handling in CMSIS OS layer (bug #975)