diff --git a/plugins/sensors/freeipmi b/plugins/sensors/freeipmi
index d821df6e..42e94729 100755
--- a/plugins/sensors/freeipmi
+++ b/plugins/sensors/freeipmi
@@ -106,11 +106,11 @@ foreach my $line (@data) {
 		value => $dataline[3],
 		label => $dataline[1]
 	       );
-  $sensor{lwarn} = $dataline[7] if $dataline[7] ne "N/A";
-  $sensor{hwarn} = $dataline[9] if $dataline[9] ne "N/A";
+  $sensor{lwarn} = $dataline[7] ne "N/A" ? $dataline[7] : '';
+  $sensor{hwarn} = $dataline[9] ne "N/A" ? $dataline[9] : '';
 
-  $sensor{lcrit} = $dataline[6] if $dataline[6] ne "N/A";
-  $sensor{hcrit} = $dataline[10] if $dataline[10] ne "N/A";
+  $sensor{lcrit} = $dataline[6] ne "N/A" ? $dataline[6] : '';
+  $sensor{hcrit} = $dataline[10] ne "N/A" ? $dataline[10] : '';
 
   my $type;
   if ( $dataline[2] eq "Temperature" ) {
@@ -149,9 +149,9 @@ END
       print "$sensor->{graphid}.label $sensor->{label}\n";
 
       print "$sensor->{graphid}.warning $sensor->{lwarn}:$sensor->{hwarn}\n"
-	if defined($sensor->{lwarn}) or defined($sensor->{hwarn});
+	unless $sensor->{lwarn} eq '' and $sensor->{hwarn} eq '';
       print "$sensor->{graphid}.critical $sensor->{lcrit}:$sensor->{hcrit}\n"
-	if defined($sensor->{lcrit}) or defined($sensor->{hcrit});
+	unless $sensor->{lcrit} eq '' and $sensor->{hcrit} eq '';
     }
   }