diff --git a/src/dump_atom.cpp b/src/dump_atom.cpp
index 3fcb8126a5..6221463920 100644
--- a/src/dump_atom.cpp
+++ b/src/dump_atom.cpp
@@ -215,9 +215,9 @@ void DumpAtom::header_item(bigint ndump)
   fprintf(fp,"ITEM: NUMBER OF ATOMS\n");
   fprintf(fp,BIGINT_FORMAT "\n",ndump);
   fprintf(fp,"ITEM: BOX BOUNDS %s\n",boundstr);
-  fprintf(fp,"%g %g\n",boxxlo,boxxhi);
-  fprintf(fp,"%g %g\n",boxylo,boxyhi);
-  fprintf(fp,"%g %g\n",boxzlo,boxzhi);
+  fprintf(fp,"%-1.16e %-1.16e\n",boxxlo,boxxhi);
+  fprintf(fp,"%-1.16e %-1.16e\n",boxylo,boxyhi);
+  fprintf(fp,"%-1.16e %-1.16e\n",boxzlo,boxzhi);
   fprintf(fp,"ITEM: ATOMS %s\n",columns);
 }
 
@@ -230,9 +230,9 @@ void DumpAtom::header_item_triclinic(bigint ndump)
   fprintf(fp,"ITEM: NUMBER OF ATOMS\n");
   fprintf(fp,BIGINT_FORMAT "\n",ndump);
   fprintf(fp,"ITEM: BOX BOUNDS xy xz yz %s\n",boundstr);
-  fprintf(fp,"%g %g %g\n",boxxlo,boxxhi,boxxy);
-  fprintf(fp,"%g %g %g\n",boxylo,boxyhi,boxxz);
-  fprintf(fp,"%g %g %g\n",boxzlo,boxzhi,boxyz);
+  fprintf(fp,"%-1.16e %-1.16e %-1.16e\n",boxxlo,boxxhi,boxxy);
+  fprintf(fp,"%-1.16e %-1.16e %-1.16e\n",boxylo,boxyhi,boxxz);
+  fprintf(fp,"%-1.16e %-1.16e %-1.16e\n",boxzlo,boxzhi,boxyz);
   fprintf(fp,"ITEM: ATOMS %s\n",columns);
 }
 
diff --git a/src/dump_custom.cpp b/src/dump_custom.cpp
index cdea7d1043..e99533eba8 100644
--- a/src/dump_custom.cpp
+++ b/src/dump_custom.cpp
@@ -400,9 +400,9 @@ void DumpCustom::header_item(bigint ndump)
   fprintf(fp,"ITEM: NUMBER OF ATOMS\n");
   fprintf(fp,BIGINT_FORMAT "\n",ndump);
   fprintf(fp,"ITEM: BOX BOUNDS %s\n",boundstr);
-  fprintf(fp,"%g %g\n",boxxlo,boxxhi);
-  fprintf(fp,"%g %g\n",boxylo,boxyhi);
-  fprintf(fp,"%g %g\n",boxzlo,boxzhi);
+  fprintf(fp,"%-1.16e %-1.16e\n",boxxlo,boxxhi);
+  fprintf(fp,"%-1.16e %-1.16e\n",boxylo,boxyhi);
+  fprintf(fp,"%-1.16e %-1.16e\n",boxzlo,boxzhi);
   fprintf(fp,"ITEM: ATOMS %s\n",columns);
 }
 
@@ -415,9 +415,9 @@ void DumpCustom::header_item_triclinic(bigint ndump)
   fprintf(fp,"ITEM: NUMBER OF ATOMS\n");
   fprintf(fp,BIGINT_FORMAT "\n",ndump);
   fprintf(fp,"ITEM: BOX BOUNDS xy xz yz %s\n",boundstr);
-  fprintf(fp,"%g %g %g\n",boxxlo,boxxhi,boxxy);
-  fprintf(fp,"%g %g %g\n",boxylo,boxyhi,boxxz);
-  fprintf(fp,"%g %g %g\n",boxzlo,boxzhi,boxyz);
+  fprintf(fp,"%-1.16e %-1.16e %-1.16e\n",boxxlo,boxxhi,boxxy);
+  fprintf(fp,"%-1.16e %-1.16e %-1.16e\n",boxylo,boxyhi,boxxz);
+  fprintf(fp,"%-1.16e %-1.16e %-1.16e\n",boxzlo,boxzhi,boxyz);
   fprintf(fp,"ITEM: ATOMS %s\n",columns);
 }
 
@@ -1073,7 +1073,8 @@ int DumpCustom::parse_fields(int narg, char **arg)
       if (!atom->molecule_flag)
         error->all(FLERR,"Dumping an atom property that isn't allocated");
       pack_choice[i] = &DumpCustom::pack_molecule;
-      vtype[i] = INT;
+      if (sizeof(tagint) == sizeof(smallint)) vtype[i] = INT;
+      else vtype[i] = BIGINT;
     } else if (strcmp(arg[iarg],"proc") == 0) {
       pack_choice[i] = &DumpCustom::pack_proc;
       vtype[i] = INT;