diff --git a/plugins/sensors/hwmon b/plugins/sensors/hwmon
index 5e755436..66e44801 100755
--- a/plugins/sensors/hwmon
+++ b/plugins/sensors/hwmon
@@ -173,7 +173,7 @@ END
     }
   }
 
-  unless ( $ENV{MUNIN_CAP_DIRTYCONFIG} == 1 ) {
+  unless ( ($ENV{MUNIN_CAP_DIRTYCONFIG} || 0) == 1 ) {
     exit 0;
   }
 }