diff --git a/src/read_dump.cpp b/src/read_dump.cpp
index 1a0a746c07..85e2312a42 100644
--- a/src/read_dump.cpp
+++ b/src/read_dump.cpp
@@ -483,51 +483,52 @@ bigint ReadDump::next(bigint ncurrent, bigint nlast, int nevery, int nskip)
 
 void ReadDump::header(int fieldinfo)
 {
-  int triclinic_snap;
+  int boxinfo, triclinic_snap;
   int fieldflag,xflag,yflag,zflag;
 
   if (filereader) {
     for (int i = 0; i < nreader; i++)
-      nsnapatoms[i] = readers[i]->read_header(box,triclinic_snap,fieldinfo,
+      nsnapatoms[i] = readers[i]->read_header(box,boxinfo,triclinic_snap,fieldinfo,
                                               nfield,fieldtype,fieldlabel,
                                               scaleflag,wrapflag,fieldflag,
                                               xflag,yflag,zflag);
   }
 
   MPI_Bcast(nsnapatoms,nreader,MPI_LMP_BIGINT,0,clustercomm);
+  MPI_Bcast(&boxinfo,1,MPI_INT,0,clustercomm);
   MPI_Bcast(&triclinic_snap,1,MPI_INT,0,clustercomm);
   MPI_Bcast(&box[0][0],9,MPI_DOUBLE,0,clustercomm);
 
   // local copy of snapshot box parameters
   // used in xfield,yfield,zfield when converting dump atom to absolute coords
 
-  xlo = box[0][0];
-  xhi = box[0][1];
-  ylo = box[1][0];
-  yhi = box[1][1];
-  zlo = box[2][0];
-  zhi = box[2][1];
-
-  // value of 1 indicates possible change in tilt factors
-
-  if (triclinic_snap == 1) {
-    xy = box[0][2];
-    xz = box[1][2];
-    yz = box[2][2];
-    double xdelta = MIN(0.0,xy);
-    xdelta = MIN(xdelta,xz);
-    xdelta = MIN(xdelta,xy+xz);
-    xlo = xlo - xdelta;
-    xdelta = MAX(0.0,xy);
-    xdelta = MAX(xdelta,xz);
-    xdelta = MAX(xdelta,xy+xz);
-    xhi = xhi - xdelta;
-    ylo = ylo - MIN(0.0,yz);
-    yhi = yhi - MAX(0.0,yz);
+  if (boxinfo) {
+    xlo = box[0][0];
+    xhi = box[0][1];
+    ylo = box[1][0];
+    yhi = box[1][1];
+    zlo = box[2][0];
+    zhi = box[2][1];
+    
+    if (triclinic_snap) {
+      xy = box[0][2];
+      xz = box[1][2];
+      yz = box[2][2];
+      double xdelta = MIN(0.0,xy);
+      xdelta = MIN(xdelta,xz);
+      xdelta = MIN(xdelta,xy+xz);
+      xlo = xlo - xdelta;
+      xdelta = MAX(0.0,xy);
+      xdelta = MAX(xdelta,xz);
+      xdelta = MAX(xdelta,xy+xz);
+      xhi = xhi - xdelta;
+      ylo = ylo - MIN(0.0,yz);
+      yhi = yhi - MAX(0.0,yz);
+    }
+    xprd = xhi - xlo;
+    yprd = yhi - ylo;
+    zprd = zhi - zlo;
   }
-  xprd = xhi - xlo;
-  yprd = yhi - ylo;
-  zprd = zhi - zlo;
 
   // done if not checking fields
 
@@ -539,13 +540,13 @@ void ReadDump::header(int fieldinfo)
   MPI_Bcast(&zflag,1,MPI_INT,0,clustercomm);
 
   // error check on current vs new box and fields
-  // triclinic_snap < 0 means no box info in file
+  // boxinfo == 0 means no box info in file
 
-  if (triclinic_snap < 0 && boxflag > 0)
-    error->all(FLERR,"No box information in dump, must use 'box no'");
-  if (triclinic_snap >= 0) {
-    if ((triclinic_snap && !triclinic) ||
-        (!triclinic_snap && triclinic))
+  if (boxflag) {
+    if (!boxinfo)
+      error->all(FLERR,"No box information in dump, must use 'box no'");
+    else if ((triclinic_snap && !triclinic) ||
+             (!triclinic_snap && triclinic))
       error->one(FLERR,"Read_dump triclinic status does not match simulation");
   }
 
diff --git a/src/reader.h b/src/reader.h
index 08b0010b81..7b31b666ba 100644
--- a/src/reader.h
+++ b/src/reader.h
@@ -29,7 +29,7 @@ class Reader : protected Pointers {
 
   virtual int read_time(bigint &) = 0;
   virtual void skip() = 0;
-  virtual bigint read_header(double [3][3], int &, int, int, int *, char **,
+  virtual bigint read_header(double [3][3], int &, int &, int, int, int *, char **,
                              int, int, int &, int &, int &, int &) = 0;
   virtual void read_atoms(int, int, double **) = 0;
 
diff --git a/src/reader_native.cpp b/src/reader_native.cpp
index 2c60ffdfd4..7c772ab6b8 100644
--- a/src/reader_native.cpp
+++ b/src/reader_native.cpp
@@ -103,7 +103,7 @@ void ReaderNative::skip()
    only called by proc 0
 ------------------------------------------------------------------------- */
 
-bigint ReaderNative::read_header(double box[3][3], int &triclinic,
+bigint ReaderNative::read_header(double box[3][3], int &boxinfo, int &triclinic, 
                                  int fieldinfo, int nfield,
                                  int *fieldtype, char **fieldlabel,
                                  int scaleflag, int wrapflag, int &fieldflag,
@@ -113,6 +113,7 @@ bigint ReaderNative::read_header(double box[3][3], int &triclinic,
   read_lines(2);
   sscanf(line,BIGINT_FORMAT,&natoms);
 
+  boxinfo = 1;
   triclinic = 0;
   box[0][2] = box[1][2] = box[2][2] = 0.0;
   read_lines(1);
diff --git a/src/reader_native.h b/src/reader_native.h
index ab99469aa8..de43e43003 100644
--- a/src/reader_native.h
+++ b/src/reader_native.h
@@ -33,7 +33,7 @@ class ReaderNative : public Reader {
 
   int read_time(bigint &);
   void skip();
-  bigint read_header(double [3][3], int &, int, int, int *, char **,
+  bigint read_header(double [3][3], int &, int &, int, int, int *, char **,
                      int, int, int &, int &, int &, int &);
   void read_atoms(int, int, double **);
 
diff --git a/src/reader_xyz.cpp b/src/reader_xyz.cpp
index 37d30bd740..303c25cd7a 100644
--- a/src/reader_xyz.cpp
+++ b/src/reader_xyz.cpp
@@ -117,7 +117,7 @@ void ReaderXYZ::skip()
    only called by proc 0
 ------------------------------------------------------------------------- */
 
-bigint ReaderXYZ::read_header(double /*box*/[3][3], int &triclinic,
+bigint ReaderXYZ::read_header(double /*box*/[3][3], int &boxinfo, int &/*triclinic*/,
                               int fieldinfo, int nfield,
                               int *fieldtype, char **/*fieldlabel*/,
                               int scaleflag, int wrapflag, int &fieldflag,
@@ -128,7 +128,7 @@ bigint ReaderXYZ::read_header(double /*box*/[3][3], int &triclinic,
 
   // signal that we have no box info at all
 
-  triclinic = -1;
+  boxinfo = 0;
 
   // if no field info requested, just return
 
diff --git a/src/reader_xyz.h b/src/reader_xyz.h
index 698c6ef240..f8b0ebcea1 100644
--- a/src/reader_xyz.h
+++ b/src/reader_xyz.h
@@ -33,7 +33,7 @@ class ReaderXYZ : public Reader {
 
   int read_time(bigint &);
   void skip();
-  bigint read_header(double [3][3], int &, int, int, int *, char **,
+  bigint read_header(double [3][3], int &, int &, int, int, int *, char **,
                      int, int, int &, int &, int &, int &);
   void read_atoms(int, int, double **);