diff --git a/src/USER-REAXC/fix_reaxc.cpp b/src/USER-REAXC/fix_reaxc.cpp
index 1323ff4da7..361733f3ca 100644
--- a/src/USER-REAXC/fix_reaxc.cpp
+++ b/src/USER-REAXC/fix_reaxc.cpp
@@ -41,16 +41,15 @@ FixReaxC::FixReaxC(LAMMPS *lmp,int narg, char **arg) :
 {
   // perform initial allocation of atom-based arrays
   // register with atom class
-
+  
+  oldnmax = 0;
   num_bonds = NULL;
   num_hbonds = NULL;
   grow_arrays(atom->nmax);
   atom->add_callback(0);
 
   // initialize arrays to MIN so atom migration is OK the 1st time
-
-  for (int i = 0; i < atom->nmax; i++)
-    num_bonds[i] = num_hbonds[i] = MIN_REAX_BONDS;
+  // it is done in grow_arrays() now
 
   // set comm sizes needed by this fix
 
@@ -98,6 +97,11 @@ void FixReaxC::grow_arrays(int nmax)
 {
   memory->grow(num_bonds,nmax,"reaxc:num_bonds");
   memory->grow(num_hbonds,nmax,"reaxc:num_hbonds");
+  for (int i = oldnmax; i < nmax; i++) {
+    num_hbonds[i] = MIN_REAX_HBONDS;
+    num_bonds[i] = MIN_REAX_BONDS;
+  }
+  oldnmax = nmax;
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/USER-REAXC/fix_reaxc.h b/src/USER-REAXC/fix_reaxc.h
index 0e173f5ece..6a37002847 100644
--- a/src/USER-REAXC/fix_reaxc.h
+++ b/src/USER-REAXC/fix_reaxc.h
@@ -56,6 +56,7 @@ class FixReaxC : public Fix {
   int maxhbonds;             // max # of Hbonds for any atom
   int *num_bonds;            // # of bonds for each atom
   int *num_hbonds;           // # of Hbonds for each atom
+  int oldnmax;               // arrays' size before growing
 };
 
 }