diff --git a/src/atoms_base.jl b/src/atoms_base.jl
index 28c1e17..7d7061b 100644
--- a/src/atoms_base.jl
+++ b/src/atoms_base.jl
@@ -5,10 +5,8 @@ using Unitful
 
 function PairList(ab::AtomsBase.AbstractSystem, cutoff::Unitful.Length; length_unit=unit(cutoff))
     cell = ustrip.(length_unit, hcat( bounding_box(ab)... )' )
-    pbc = map( boundary_conditions(ab) ) do x
-        x == Periodic()
-    end
-    r = map( 1:length(ab)) do i
+    pbc = periodicity(ab)
+    r = map( 1:length(ab) ) do i
         # Need to have SVector here for PairList to work
         # if position does not give SVector
         SVector( ustrip.(length_unit, position(ab,i))...)