diff --git a/src/Makefile b/src/Makefile
index 64e5bec97c6ca97d6c24beeebfdb93c77140631a..756f7956abb272b1108318a71a880881bedf72a5 100755
--- a/src/Makefile
+++ b/src/Makefile
@@ -47,7 +47,7 @@ PACKAGE = asphere body class2 colloid compress coreshell dipole fld gpu \
 	  python qeq reax replica rigid shock snap srd voronoi xtc
 
 PACKUSER = user-atc user-awpmd user-cg-cmm user-colvars user-cuda \
-	   user-diffraction user-drude user-eff user-fep user-h5md \
+	   user-diffraction user-dpd user-drude user-eff user-fep user-h5md \
 	   user-intel user-lb user-mgpt \
 	   user-misc user-molfile user-omp user-phonon user-qmmm user-qtb \
 	   user-quip user-reaxc user-smd user-smtbq user-sph user-tally
diff --git a/src/neighbor.h b/src/neighbor.h
index deba569916c15b57f6dbf59239befe6d818f8ae5..bb944b7a3b356600e73aac80d36fa8162fcb8a8a 100644
--- a/src/neighbor.h
+++ b/src/neighbor.h
@@ -94,6 +94,10 @@ class Neighbor : protected Pointers {
   bigint memory_usage();
   int exclude_setting();
 
+  // USER-DPD package
+
+  void assign_ssa_airnums();       // set ssa_airnum values
+
  protected:
   int me,nprocs;
 
@@ -325,7 +329,6 @@ class Neighbor : protected Pointers {
   // SSA neighboring for USER-DPD
 
   int coord2ssa_airnum(double *);  // map atom coord to an AIR number
-  void assign_ssa_airnums();       // set ssa_airnum values
 
   void half_bin_newton_ssa(NeighList *);
   void half_from_full_newton_ssa(class NeighList *);