diff --git a/openmc/material.py b/openmc/material.py
index 6edc372161..4b871b77d6 100644
--- a/openmc/material.py
+++ b/openmc/material.py
@@ -519,6 +519,7 @@ class Material(IDManagerMixin):
         cv.check_type('nuclide', nuclide, str)
         cv.check_type('percent', percent, Real)
         cv.check_value('percent type', percent_type, {'ao', 'wo'})
+        cv.check_greater_than('percent', percent, 0, equality=True)
 
         if self._macroscopic is not None:
             msg = 'Unable to add a Nuclide to Material ID="{}" as a ' \
@@ -727,6 +728,7 @@ class Material(IDManagerMixin):
 
         cv.check_type('nuclide', element, str)
         cv.check_type('percent', percent, Real)
+        cv.check_greater_than('percent', percent, 0, equality=True)
         cv.check_value('percent type', percent_type, {'ao', 'wo'})
 
         # Make sure element name is just that