diff --git a/shimatta_kenkyusho/parts/forms.py b/shimatta_kenkyusho/parts/forms.py
index 5be0176..cdc264a 100644
--- a/shimatta_kenkyusho/parts/forms.py
+++ b/shimatta_kenkyusho/parts/forms.py
@@ -99,7 +99,7 @@ class AddStockForm(forms.Form):
         amount = self.cleaned_data.get('amount')
         watermark = -1
 
-        if self.cleaned_data.get('watermark-active'):
+        if self.cleaned_data.get('watermark_active'):
             watermark = self.cleaned_data.get('watermark')
 
         new_stock = parts_models.Stock.objects.create(storage=storage, component=component, watermark=watermark, amount=amount)