diff --git a/oscar/SleepLib/loader_plugins/resmed_loader.cpp b/oscar/SleepLib/loader_plugins/resmed_loader.cpp
index d75f38e7..826fd0ab 100644
--- a/oscar/SleepLib/loader_plugins/resmed_loader.cpp
+++ b/oscar/SleepLib/loader_plugins/resmed_loader.cpp
@@ -1366,7 +1366,7 @@ void ResDayTask::run()
         for (int i=0;i<resday->str.maskon.size();++i) {
             quint32 maskon = resday->str.maskon[i];
             quint32 maskoff = resday->str.maskoff[i];
-            if ((maskon>0) && (maskoff>0)) {
+            if (((maskon>0) && (maskoff>0)) && (maskon != maskoff)) {
                 Session * sess = new Session(mach, maskon);
                 sess->set_first(quint64(maskon) * 1000L);
                 sess->set_last(quint64(maskoff) * 1000L);