diff --git a/fhem/FHEM/00_OWX.pm b/fhem/FHEM/00_OWX.pm
index 39ae941dc..9d3eb216a 100644
--- a/fhem/FHEM/00_OWX.pm
+++ b/fhem/FHEM/00_OWX.pm
@@ -193,9 +193,12 @@ sub OWX_Define ($$) {
     $hash->{HWDEVICE}   = $owx_hwdevice;
   #-- check if we are connecting to Arduino (via FRM):
   } elsif ($dev =~ /^\d{1,2}$/) {
-  	require "10_FRM.pm";
-  	$hash->{INTERFACE} = "firmata";
-    FRM_Client_Define($hash,$def);
+  	if (defined $main::modules{FRM}) {
+  		$hash->{INTERFACE} = "firmata";
+    	FRM_Client_Define($hash,$def);
+  	} else {
+  		Log 1,"module FRM not yet loaded, please define an FRM device first.";
+  	}
   } else {
     $hash->{DeviceName} = $dev;
     #-- Second step in case of CUNO: See if we can open it