diff --git a/NEWS.md b/NEWS.md
index 33e2d76bf..3160fd0a3 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -4,6 +4,8 @@
 
 - Report part 5: fix bug that was introduced on 2024-Feb-19 in the calculation of wear percentage #1148
 
+- Report part 5: Rename variable sleep_efficiency to sleep_efficiency_after_onset, #1157
+
 - Vignette: Migrated many sections from main CRAN vignette to wadpac.github.io/GGIR/
 
 # CHANGES IN GGIR VERSION 3.1-1
diff --git a/R/g.part5_analyseSegment.R b/R/g.part5_analyseSegment.R
index 12c242a5d..f806da8a2 100644
--- a/R/g.part5_analyseSegment.R
+++ b/R/g.part5_analyseSegment.R
@@ -186,7 +186,7 @@ g.part5_analyseSegment = function(indexlog, timeList, levelList,
     # sleep efficiency
     dsummary[si,fi] = length(which(ts$sibdetection[sse] == 1 &
                                      ts$diur[sse] == 1)) / length(which(ts$diur[sse] == 1))
-    ds_names[fi] = "sleep_efficiency";      fi = fi + 1
+    ds_names[fi] = "sleep_efficiency_after_onset";      fi = fi + 1
     #===============================================
     # NAPS (estimation)
     if (params_output[["do.sibreport"]] == TRUE & "nap1_nonwear2" %in% colnames(ts) &