diff --git a/mrdna/segmentmodel.py b/mrdna/segmentmodel.py
index 53247068a516975df21fa541ca85f3d84c48eee9..b2f84303d2fb1039f15d7261a7b2780ccf207c5b 100644
--- a/mrdna/segmentmodel.py
+++ b/mrdna/segmentmodel.py
@@ -1347,7 +1347,7 @@ class SegmentModel(ArbdModel):
                 raise Exception("Unhandled potential type '%s'" % type_)
         return self._bonded_potential[key]
     def get_bond_potential(self, kSpring, d):
-        assert( d > 1 )
+        assert( d > 0.2 )
         return self._get_potential("bond", kSpring, d)
     def get_angle_potential(self, kSpring, d):
         return self._get_potential("angle", kSpring, d)