diff --git a/CircularZone/CircularZone.py b/CircularZone/CircularZone.py
index 43f46f6..749da3d 100644
--- a/CircularZone/CircularZone.py
+++ b/CircularZone/CircularZone.py
@@ -41,7 +41,7 @@ class CircularZone(pcbnew.ActionPlugin):
         val = None
         try:
             val = float(value)
-            if val < 1:
+            if val == 0:
                 raise Exception("Invalid")
         except:
             self.Warn(