diff --git a/fhem/fhem.pl b/fhem/fhem.pl
index 4bf72460d..d4afeb1be 100755
--- a/fhem/fhem.pl
+++ b/fhem/fhem.pl
@@ -134,6 +134,7 @@ sub readingsBeginUpdate($);
 sub readingsBulkUpdate($$$@);
 sub readingsEndUpdate($$);
 sub readingsSingleUpdate($$$$);
+sub readingsDelete($$);
 sub redirectStdinStdErr();
 sub rejectDuplicate($$$);
 sub resolveAttrRename($$);
@@ -4589,6 +4590,13 @@ readingsSingleUpdate($$$$)
   return $rv;
 }
 
+sub
+readingsDelete($$)
+{
+  my ($hash,$reading) = @_;
+  delete $hash->{READINGS}{$reading};
+}
+
 ##############################################################################
 #
 # date and time routines