diff --git a/src/neigh_list.cpp b/src/neigh_list.cpp
index 2c26035cba..dbd8f0d4a0 100644
--- a/src/neigh_list.cpp
+++ b/src/neigh_list.cpp
@@ -124,6 +124,7 @@ void NeighList::grow(int nmax)
   memory->destroy(ilist);
   memory->destroy(numneigh);
   memory->sfree(firstneigh);
+  memory->sfree(firstdouble);
 
   memory->create(ilist,maxatoms,"neighlist:ilist");
   memory->create(numneigh,maxatoms,"neighlist:numneigh");