diff --git a/src/read_dump.cpp b/src/read_dump.cpp
index 395f4c8edd..1a0a746c07 100644
--- a/src/read_dump.cpp
+++ b/src/read_dump.cpp
@@ -507,7 +507,10 @@ void ReadDump::header(int fieldinfo)
   yhi = box[1][1];
   zlo = box[2][0];
   zhi = box[2][1];
-  if (triclinic_snap) {
+
+  // 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];
@@ -546,7 +549,7 @@ void ReadDump::header(int fieldinfo)
       error->one(FLERR,"Read_dump triclinic status does not match simulation");
   }
 
-  // error check on requested fields exisiting in dump file
+  // error check on requested fields existing in dump file
 
   if (fieldflag < 0)
     error->one(FLERR,"Read_dump field not found in dump file");
diff --git a/src/reader.cpp b/src/reader.cpp
index cf344b37b3..5292c9c992 100644
--- a/src/reader.cpp
+++ b/src/reader.cpp
@@ -75,3 +75,13 @@ void Reader::close_file()
   else fclose(fp);
   fp = NULL;
 }
+
+/* ----------------------------------------------------------------------
+   detect unused arguments
+------------------------------------------------------------------------- */
+
+void Reader::settings(int narg, char** /*args*/)
+{
+  if (narg > 0)
+    error->all(FLERR,"Illegal read_dump command");
+}
diff --git a/src/reader.h b/src/reader.h
index 8f36bf622a..08b0010b81 100644
--- a/src/reader.h
+++ b/src/reader.h
@@ -25,7 +25,7 @@ class Reader : protected Pointers {
   Reader(class LAMMPS *);
   virtual ~Reader() {}
 
-  virtual void settings(int, char**) {};
+  virtual void settings(int, char**);
 
   virtual int read_time(bigint &) = 0;
   virtual void skip() = 0;