diff --git a/src/MANYBODY/pair_comb.cpp b/src/MANYBODY/pair_comb.cpp
index 53e08afe18..837a1d316f 100644
--- a/src/MANYBODY/pair_comb.cpp
+++ b/src/MANYBODY/pair_comb.cpp
@@ -592,7 +592,7 @@ void PairComb::read_file(char *file)
     PotentialFileReader reader(lmp, file, "COMB");
     char * line;
 
-    while(line = reader.next_line(Param::NPARAMS_PER_LINE)) {
+    while(line = reader.next_line(NPARAMS_PER_LINE)) {
       try {
         ValueTokenizer values(line," \t\n\r\f");
 
diff --git a/src/MANYBODY/pair_comb.h b/src/MANYBODY/pair_comb.h
index ec4e362f0b..7a3d279033 100644
--- a/src/MANYBODY/pair_comb.h
+++ b/src/MANYBODY/pair_comb.h
@@ -38,6 +38,9 @@ class PairComb : public Pair {
   virtual double yasu_char(double *, int &);
   double enegtot;
 
+  static const int NPARAMS_PER_LINE = 49;
+
+ protected:
   struct Param {
     double lam11,lam12,lam21,lam22;
     double c,d,h;
@@ -56,10 +59,8 @@ class PairComb : public Pair {
     double coulcut, lcut, lcutsq, hfocor;
     int ielement,jelement,kelement;
     int powermint;
-    static const int NPARAMS_PER_LINE = 49;
   };
 
- protected:
   double cutmax;                // max cutoff for all elements
   int nelements;                // # of unique elements
   char **elements;              // names of unique elements
diff --git a/src/MANYBODY/pair_comb3.cpp b/src/MANYBODY/pair_comb3.cpp
index 28af9adab9..148344b922 100644
--- a/src/MANYBODY/pair_comb3.cpp
+++ b/src/MANYBODY/pair_comb3.cpp
@@ -591,7 +591,7 @@ void PairComb3::read_file(char *file)
     PotentialFileReader reader(lmp, file, "COMB3");
     char * line;
 
-    while(line = reader.next_line(Param::NPARAMS_PER_LINE)) {
+    while(line = reader.next_line(NPARAMS_PER_LINE)) {
       try {
         ValueTokenizer values(line, " \t\n\r\f");
 
diff --git a/src/MANYBODY/pair_comb3.h b/src/MANYBODY/pair_comb3.h
index bade95e88c..567859127b 100644
--- a/src/MANYBODY/pair_comb3.h
+++ b/src/MANYBODY/pair_comb3.h
@@ -37,6 +37,9 @@ class PairComb3 : public Pair {
   virtual double combqeq(double *, int &);
   double enegtot;
 
+  static const int NPARAMS_PER_LINE = 74;
+
+ protected:
  // general potential parameters
   struct Param {
     int ielement,jelement,kelement,powermint;
@@ -55,11 +58,8 @@ class PairComb3 : public Pair {
     double veps, vsig, pcna, pcnb, pcnc, pcnd, polz, curl, pcross;
     double paaa, pbbb;
     double curlcut1, curlcut2, curl0;
-    static const int NPARAMS_PER_LINE = 74;
   };
 
- protected:
-
   // general setups
   int nelements;                        // # of unique elements
   int ***elem2param;                    // mapping from element triplets to parameters
diff --git a/src/MANYBODY/pair_sw.cpp b/src/MANYBODY/pair_sw.cpp
index bf6c0f63bc..f79f835ad0 100644
--- a/src/MANYBODY/pair_sw.cpp
+++ b/src/MANYBODY/pair_sw.cpp
@@ -358,7 +358,7 @@ void PairSW::read_file(char *file)
     PotentialFileReader reader(lmp, file, "Stillinger-Weber");
     char * line;
 
-    while(line = reader.next_line(Param::NPARAMS_PER_LINE)) {
+    while(line = reader.next_line(NPARAMS_PER_LINE)) {
       try {
         ValueTokenizer values(line, " \t\n\r\f");
 
diff --git a/src/MANYBODY/pair_sw.h b/src/MANYBODY/pair_sw.h
index 5b793dbc76..b3ecebe3b9 100644
--- a/src/MANYBODY/pair_sw.h
+++ b/src/MANYBODY/pair_sw.h
@@ -34,6 +34,9 @@ class PairSW : public Pair {
   virtual double init_one(int, int);
   virtual void init_style();
 
+  static const int NPARAMS_PER_LINE = 14;
+
+ protected:
   struct Param {
     double epsilon,sigma;
     double littlea,lambda,gamma,costheta;
@@ -44,10 +47,8 @@ class PairSW : public Pair {
     double sigma_gamma,lambda_epsilon,lambda_epsilon2;
     double c1,c2,c3,c4,c5,c6;
     int ielement,jelement,kelement;
-    static const int NPARAMS_PER_LINE = 14;
   };
 
- protected:
   double cutmax;                // max cutoff for all elements
   int nelements;                // # of unique elements
   char **elements;              // names of unique elements
diff --git a/src/MANYBODY/pair_tersoff.cpp b/src/MANYBODY/pair_tersoff.cpp
index a920ba526b..4b3fd444c6 100644
--- a/src/MANYBODY/pair_tersoff.cpp
+++ b/src/MANYBODY/pair_tersoff.cpp
@@ -404,7 +404,7 @@ void PairTersoff::read_file(char *file)
     PotentialFileReader reader(lmp, file, "Tersoff");
     char * line;
 
-    while(line = reader.next_line(Param::NPARAMS_PER_LINE)) {
+    while(line = reader.next_line(NPARAMS_PER_LINE)) {
       try {
         ValueTokenizer values(line, " \t\n\r\f");
 
diff --git a/src/MANYBODY/pair_tersoff.h b/src/MANYBODY/pair_tersoff.h
index 2692a026b0..d4ae28ee6d 100644
--- a/src/MANYBODY/pair_tersoff.h
+++ b/src/MANYBODY/pair_tersoff.h
@@ -34,6 +34,10 @@ class PairTersoff : public Pair {
   virtual void init_style();
   double init_one(int, int);
 
+  static const int NPARAMS_PER_LINE = 17;
+
+ protected:
+ 
   struct Param {
     double lam1,lam2,lam3;
     double c,d,h;
@@ -49,10 +53,8 @@ class PairTersoff : public Pair {
     double c5,ca1,ca4;           // added for TersoffMOD
     double powern_del;
     double c0;                   // added for TersoffMODC
-    static const int NPARAMS_PER_LINE = 17;
   };
 
- protected:
   Param *params;                // parameter set for an I-J-K interaction
   char **elements;              // names of unique elements
   int ***elem2param;            // mapping from element triplets to parameters
diff --git a/src/MANYBODY/pair_tersoff_mod.cpp b/src/MANYBODY/pair_tersoff_mod.cpp
index d6d097727b..1bd010fcbc 100644
--- a/src/MANYBODY/pair_tersoff_mod.cpp
+++ b/src/MANYBODY/pair_tersoff_mod.cpp
@@ -45,7 +45,7 @@ PairTersoffMOD::PairTersoffMOD(LAMMPS *lmp) : PairTersoff(lmp) {}
 
 void PairTersoffMOD::read_file(char *file)
 {
-  int params_per_line = 20;
+  int params_per_line = NPARAMS_PER_LINE;
   char **words = new char*[params_per_line+1];
 
   memory->sfree(params);
diff --git a/src/MANYBODY/pair_tersoff_mod.h b/src/MANYBODY/pair_tersoff_mod.h
index 162603bc5c..2cdbae9518 100644
--- a/src/MANYBODY/pair_tersoff_mod.h
+++ b/src/MANYBODY/pair_tersoff_mod.h
@@ -30,6 +30,8 @@ class PairTersoffMOD : public PairTersoff {
   PairTersoffMOD(class LAMMPS *);
   ~PairTersoffMOD() {}
 
+  static const int NPARAMS_PER_LINE = 20;
+
  protected:
   virtual void read_file(char *);
   virtual void setup_params();
diff --git a/unittest/formats/test_potential_file_reader.cpp b/unittest/formats/test_potential_file_reader.cpp
index 21b7f572e0..210c8a6acd 100644
--- a/unittest/formats/test_potential_file_reader.cpp
+++ b/unittest/formats/test_potential_file_reader.cpp
@@ -7,15 +7,17 @@
 #include "MANYBODY/pair_comb.h"
 #include "MANYBODY/pair_comb3.h"
 #include "MANYBODY/pair_tersoff.h"
+#include "MANYBODY/pair_tersoff_mod.h"
 
 #include <mpi.h>
 
 using namespace LAMMPS_NS;
 
-const int LAMMPS_NS::PairSW::Param::NPARAMS_PER_LINE;
-const int LAMMPS_NS::PairComb::Param::NPARAMS_PER_LINE;
-const int LAMMPS_NS::PairComb3::Param::NPARAMS_PER_LINE;
-const int LAMMPS_NS::PairTersoff::Param::NPARAMS_PER_LINE;
+const int LAMMPS_NS::PairSW::NPARAMS_PER_LINE;
+const int LAMMPS_NS::PairComb::NPARAMS_PER_LINE;
+const int LAMMPS_NS::PairComb3::NPARAMS_PER_LINE;
+const int LAMMPS_NS::PairTersoff::NPARAMS_PER_LINE;
+const int LAMMPS_NS::PairTersoffMOD::NPARAMS_PER_LINE;
 
 class PotenialFileReaderTest : public ::testing::Test {
 protected:
@@ -42,8 +44,8 @@ TEST_F(PotenialFileReaderTest, Si) {
     PotentialFileReader reader(lmp, "Si.sw", "Stillinger-Weber");
     ::testing::internal::GetCapturedStdout();
 
-    auto line = reader.next_line(PairSW::Param::NPARAMS_PER_LINE);
-    ASSERT_EQ(utils::count_words(line), PairSW::Param::NPARAMS_PER_LINE);
+    auto line = reader.next_line(PairSW::NPARAMS_PER_LINE);
+    ASSERT_EQ(utils::count_words(line), PairSW::NPARAMS_PER_LINE);
 }
 
 TEST_F(PotenialFileReaderTest, Comb) {
@@ -51,8 +53,8 @@ TEST_F(PotenialFileReaderTest, Comb) {
     PotentialFileReader reader(lmp, "ffield.comb", "COMB");
     ::testing::internal::GetCapturedStdout();
 
-    auto line = reader.next_line(PairComb::Param::NPARAMS_PER_LINE);
-    ASSERT_EQ(utils::count_words(line), PairComb::Param::NPARAMS_PER_LINE);
+    auto line = reader.next_line(PairComb::NPARAMS_PER_LINE);
+    ASSERT_EQ(utils::count_words(line), PairComb::NPARAMS_PER_LINE);
 }
 
 TEST_F(PotenialFileReaderTest, Comb3) {
@@ -60,8 +62,8 @@ TEST_F(PotenialFileReaderTest, Comb3) {
     PotentialFileReader reader(lmp, "ffield.comb3", "COMB3");
     ::testing::internal::GetCapturedStdout();
 
-    auto line = reader.next_line(PairComb3::Param::NPARAMS_PER_LINE);
-    ASSERT_EQ(utils::count_words(line), PairComb3::Param::NPARAMS_PER_LINE);
+    auto line = reader.next_line(PairComb3::NPARAMS_PER_LINE);
+    ASSERT_EQ(utils::count_words(line), PairComb3::NPARAMS_PER_LINE);
 }
 
 TEST_F(PotenialFileReaderTest, Tersoff) {
@@ -69,8 +71,17 @@ TEST_F(PotenialFileReaderTest, Tersoff) {
     PotentialFileReader reader(lmp, "Si.tersoff", "Tersoff");
     ::testing::internal::GetCapturedStdout();
 
-    auto line = reader.next_line(PairTersoff::Param::NPARAMS_PER_LINE);
-    ASSERT_EQ(utils::count_words(line), PairTersoff::Param::NPARAMS_PER_LINE);
+    auto line = reader.next_line(PairTersoff::NPARAMS_PER_LINE);
+    ASSERT_EQ(utils::count_words(line), PairTersoff::NPARAMS_PER_LINE);
+}
+
+TEST_F(PotenialFileReaderTest, TersoffMod) {
+    ::testing::internal::CaptureStdout();
+    PotentialFileReader reader(lmp, "Si.tersoff.mod", "Tersoff");
+    ::testing::internal::GetCapturedStdout();
+
+    auto line = reader.next_line(PairTersoffMOD::NPARAMS_PER_LINE);
+    ASSERT_EQ(utils::count_words(line), PairTersoffMOD::NPARAMS_PER_LINE);
 }
 
 int main(int argc, char **argv)