diff --git a/fhem/docs/commandref_frame.html b/fhem/docs/commandref_frame.html
index 51dd72e82..1dfb3371c 100644
--- a/fhem/docs/commandref_frame.html
+++ b/fhem/docs/commandref_frame.html
@@ -601,7 +601,10 @@ attribute list if you want to know if a device supports these attributes.  <br>
     This attribute takes a comma-separated list of readings. You may use
     regular expressions in that list. For each reading in the list FHEM will
     internaly store the previous value if the readings value changes. To access
-    the storead value use the OldReadings.* functions.</li>
+    the storead value use the OldReadings.* functions.
+    If the previous value is always to be stored (even if it didn't changed),
+    then set the last value of the comma-separated list to oldreadingsAlways.
+    </li>
 
     <a name="userReadings"></a>
     <li>userReadings<br>
diff --git a/fhem/docs/commandref_frame_DE.html b/fhem/docs/commandref_frame_DE.html
index 61aaf3d97..ccebd0996 100644
--- a/fhem/docs/commandref_frame_DE.html
+++ b/fhem/docs/commandref_frame_DE.html
@@ -609,6 +609,9 @@ Ger&auml;t dokumentiert.
     Readings.  regex sind erlaubt. F&uuml;r jedes Reading aus der Liste
     speichert FHEM intern den vorherigen Wert wenn sich das Reading
     &auml;ndert. Zum Zugriff auf die Werte gibt es die OldReadings.* Routinen.
+    Falls der vorherige Wert immer, d.h. auch wenn es sich nicht &auml;ndert,
+    gespeichert werden soll, dann muss der letzte Werte der Komma getrennten
+    Liste oldreadingsAlways sein.
     </li>     
 
     <a name="userReadings"></a>
diff --git a/fhem/fhem.pl b/fhem/fhem.pl
index 12a594832..9adcec877 100755
--- a/fhem/fhem.pl
+++ b/fhem/fhem.pl
@@ -4799,12 +4799,15 @@ setReadingsVal($$$$)
 
   return if($rname eq "IODev" && !fhem_devSupportsAttr($hash->{NAME}, "IODev"));
 
-  if($hash->{".or"} && grep($rname =~ m/^$_$/, @{$hash->{".or"}}) ) {
-    if(defined($hash->{READINGS}{$rname}) && 
-       defined($hash->{READINGS}{$rname}{VAL}) &&
-        $hash->{READINGS}{$rname}{VAL} ne $val ) {
-      $hash->{OLDREADINGS}{$rname}{VAL} = $hash->{READINGS}{$rname}{VAL};
-      $hash->{OLDREADINGS}{$rname}{TIME} = $hash->{READINGS}{$rname}{TIME};
+  my $or = $hash->{".or"};
+  if($or && grep($rname =~ m/^$_$/, @{$or}) ) {
+    my $rd = $hash->{READINGS};
+    if(defined($rd->{$rname}) && 
+       defined($rd->{$rname}{VAL}) &&
+        ($or->[@{$or}-1] eq "oldreadingsAlways" ||
+         $rd->{$rname}{VAL} ne $val) ) {
+      $hash->{OLDREADINGS}{$rname}{VAL} = $rd->{$rname}{VAL};
+      $hash->{OLDREADINGS}{$rname}{TIME} = $rd->{$rname}{TIME};
     }
   }