diff --git a/fhem/FHEM/10_CUL_HM.pm b/fhem/FHEM/10_CUL_HM.pm
index c2a5e153f..6535056fd 100755
--- a/fhem/FHEM/10_CUL_HM.pm
+++ b/fhem/FHEM/10_CUL_HM.pm
@@ -94,6 +94,7 @@ sub CUL_HM_getChnLvl($);
 sub CUL_HM_initRegHash();
 sub CUL_HM_fltCvT($);
 sub CUL_HM_CvTflt($);
+sub CUL_HM_getRegN($$@);
 sub CUL_HM_4DisText($);
 sub CUL_HM_TCtempReadings($);
 sub CUL_HM_repReadings($);