diff --git a/src/MANYBODY/pair_airebo.cpp b/src/MANYBODY/pair_airebo.cpp
index cd3ecf8ffa..e0aa9a628a 100644
--- a/src/MANYBODY/pair_airebo.cpp
+++ b/src/MANYBODY/pair_airebo.cpp
@@ -3378,7 +3378,7 @@ void PairAIREBO::read_file(char *filename)
       break;
 
     default:
-      error->one(FLERR, fmt::format("Unknown REBO style variant %d",variant).c_str());
+      error->one(FLERR, fmt::format("Unknown REBO style variant %d",variant));
     }
 
     PotentialFileReader reader(lmp, filename, potential_name);
@@ -3390,7 +3390,7 @@ void PairAIREBO::read_file(char *filename)
     char * line = reader.next_line();
 
     if (std::string(line).find(header) == std::string::npos) {
-      error->one(FLERR,fmt::format("Potential file does not match AIREBO/REBO style variant: {}: {}", header, line).c_str());
+      error->one(FLERR, fmt::format("Potential file does not match AIREBO/REBO style variant: {}: {}", header, line));
     }
 
     // skip remaining comments
diff --git a/src/MANYBODY/pair_eim.cpp b/src/MANYBODY/pair_eim.cpp
index 730c184a43..0d552caebc 100644
--- a/src/MANYBODY/pair_eim.cpp
+++ b/src/MANYBODY/pair_eim.cpp
@@ -29,6 +29,7 @@
 #include "utils.h"
 #include "tokenizer.h"
 #include "potential_file_reader.h"
+#include "fmt/format.h"
 
 using namespace LAMMPS_NS;
 
@@ -1059,9 +1060,7 @@ EIMPotentialFileReader::EIMPotentialFileReader(LAMMPS * lmp, const std::string &
   FILE * fp = force->open_potential(filename.c_str());
 
   if (fp == NULL) {
-    char str[128];
-    snprintf(str, 128, "cannot open EIM potential file %s", filename.c_str());
-    error->one(FLERR, str);
+    error->one(FLERR, fmt::format("cannot open EIM potential file {}", filename));
   }
 
   parse(fp);
diff --git a/src/MOLECULE/bond_table.cpp b/src/MOLECULE/bond_table.cpp
index 66ac30df2c..ffee4335c7 100644
--- a/src/MOLECULE/bond_table.cpp
+++ b/src/MOLECULE/bond_table.cpp
@@ -380,7 +380,7 @@ void BondTable::read_table(Table *tb, char *file, char *keyword)
   if (ferror) {
     std::string str = fmt::format("%d of %d force values in table are inconsistent with -dE/dr.\n"
                                   "  Should only be flagged at inflection points",ferror,tb->ninput);
-    error->warning(FLERR,str.c_str());
+    error->warning(FLERR, str);
   }
 
   // warn if data was read incompletely, e.g. columns were missing
diff --git a/src/USER-MISC/dihedral_table.cpp b/src/USER-MISC/dihedral_table.cpp
index 7875560ee6..9fd3679106 100644
--- a/src/USER-MISC/dihedral_table.cpp
+++ b/src/USER-MISC/dihedral_table.cpp
@@ -832,13 +832,13 @@ void DihedralTable::coeff(int narg, char **arg)
     string err_msg;
     err_msg = string("Invalid dihedral table length (")
       + string(arg[2]) + string(").");
-    error->one(FLERR,err_msg.c_str());
+    error->one(FLERR,err_msg);
   }
   else if ((tb->ninput == 2) && (tabstyle == SPLINE)) {
     string err_msg;
     err_msg = string("Invalid dihedral spline table length. (Try linear)\n (")
       + string(arg[2]) + string(").");
-    error->one(FLERR,err_msg.c_str());
+    error->one(FLERR,err_msg);
   }
 
   // check for monotonicity
@@ -851,7 +851,7 @@ void DihedralTable::coeff(int narg, char **arg)
         string(arg[2]) + string(", ")+i_str.str()+string("th entry)");
       if (i==0)
         err_msg += string("\n(This is probably a mistake with your table format.)\n");
-      error->all(FLERR,err_msg.c_str());
+      error->all(FLERR,err_msg);
     }
   }
 
@@ -863,7 +863,7 @@ void DihedralTable::coeff(int narg, char **arg)
       string err_msg;
       err_msg = string("Dihedral table angle range must be < 360 degrees (")
         +string(arg[2]) + string(").");
-      error->all(FLERR,err_msg.c_str());
+      error->all(FLERR,err_msg);
     }
   }
   else {
@@ -871,7 +871,7 @@ void DihedralTable::coeff(int narg, char **arg)
       string err_msg;
       err_msg = string("Dihedral table angle range must be < 2*PI radians (")
         + string(arg[2]) + string(").");
-      error->all(FLERR,err_msg.c_str());
+      error->all(FLERR,err_msg);
     }
   }
 
@@ -1214,7 +1214,7 @@ void DihedralTable::spline_table(Table *tb)
 
     if ((num_disagreements > tb->ninput/2) && (num_disagreements > 2)) {
       string msg("Dihedral table has inconsistent forces and energies. (Try \"NOF\".)\n");
-      error->all(FLERR,msg.c_str());
+      error->all(FLERR, msg);
     }
 
   } // check for consistency if (! tb->f_unspecified)
@@ -1344,7 +1344,7 @@ void DihedralTable::param_extract(Table *tb, char *line)
       //}
       else {
         string err_msg = fmt::format("Invalid keyword in dihedral angle table parameters ({})", word);
-        error->one(FLERR,err_msg.c_str());
+        error->one(FLERR,err_msg);
       }
     }
   } catch (TokenizerException & e) {
diff --git a/src/USER-MISC/dihedral_table_cut.cpp b/src/USER-MISC/dihedral_table_cut.cpp
index 194c25f536..e2283633bc 100644
--- a/src/USER-MISC/dihedral_table_cut.cpp
+++ b/src/USER-MISC/dihedral_table_cut.cpp
@@ -824,13 +824,13 @@ void DihedralTableCut::coeff(int narg, char **arg)
     string err_msg;
     err_msg = string("Invalid dihedral table length (")
       + string(arg[5]) + string(").");
-    error->one(FLERR,err_msg.c_str());
+    error->one(FLERR,err_msg);
   }
   else if ((tb->ninput == 2) && (tabstyle == SPLINE)) {
     string err_msg;
     err_msg = string("Invalid dihedral spline table length. (Try linear)\n (")
       + string(arg[5]) + string(").");
-    error->one(FLERR,err_msg.c_str());
+    error->one(FLERR,err_msg);
   }
 
   // check for monotonicity
@@ -843,7 +843,7 @@ void DihedralTableCut::coeff(int narg, char **arg)
         string(arg[5]) + string(", ")+i_str.str()+string("th entry)");
       if (i==0)
         err_msg += string("\n(This is probably a mistake with your table format.)\n");
-      error->all(FLERR,err_msg.c_str());
+      error->all(FLERR,err_msg);
     }
   }
 
@@ -855,7 +855,7 @@ void DihedralTableCut::coeff(int narg, char **arg)
       string err_msg;
       err_msg = string("Dihedral table angle range must be < 360 degrees (")
         +string(arg[5]) + string(").");
-      error->all(FLERR,err_msg.c_str());
+      error->all(FLERR,err_msg);
     }
   }
   else {
@@ -863,7 +863,7 @@ void DihedralTableCut::coeff(int narg, char **arg)
       string err_msg;
       err_msg = string("Dihedral table angle range must be < 2*PI radians (")
         + string(arg[5]) + string(").");
-      error->all(FLERR,err_msg.c_str());
+      error->all(FLERR,err_msg);
     }
   }
 
@@ -1081,7 +1081,7 @@ void DihedralTableCut::read_table(Table *tb, char *file, char *keyword)
   FILE *fp = force->open_potential(file);
   if (fp == NULL) {
     string err_msg = string("Cannot open file ") + string(file);
-    error->one(FLERR,err_msg.c_str());
+    error->one(FLERR,err_msg);
   }
 
   // loop until section found with matching keyword
@@ -1090,7 +1090,7 @@ void DihedralTableCut::read_table(Table *tb, char *file, char *keyword)
     if (fgets(line,MAXLINE,fp) == NULL) {
       string err_msg=string("Did not find keyword \"")
         +string(keyword)+string("\" in dihedral table file.");
-      error->one(FLERR, err_msg.c_str());
+      error->one(FLERR, err_msg);
     }
     if (strspn(line," \t\n\r") == strlen(line)) continue;  // blank line
     if (line[0] == '#') continue;                          // comment
@@ -1376,7 +1376,7 @@ void DihedralTableCut::param_extract(Table *tb, char *line)
     else {
       string err_msg("Invalid keyword in dihedral angle table parameters");
       err_msg += string(" (") + string(word) + string(")");
-      error->one(FLERR,err_msg.c_str());
+      error->one(FLERR, err_msg);
     }
     word = strtok(NULL," \t\n\r\f");
   }
diff --git a/src/utils.cpp b/src/utils.cpp
index ec2f6b12a4..a8dc4e308e 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -156,7 +156,7 @@ void utils::sfgets(const char *srcname, int srcline, char *s, int size,
     errmsg += filename;
     errmsg += "'";
 
-    if (error) error->one(srcname,srcline,errmsg.c_str());
+    if (error) error->one(srcname,srcline,errmsg);
     if (s) *s = '\0'; // truncate string to empty in case error is NULL
   }
   return;
@@ -185,7 +185,7 @@ void utils::sfread(const char *srcname, int srcline, void *s, size_t size,
     errmsg += filename;
     errmsg += "'";
 
-    if (error) error->one(srcname,srcline,errmsg.c_str());
+    if (error) error->one(srcname,srcline,errmsg);
   }
   return;
 }
@@ -239,9 +239,9 @@ double utils::numeric(const char *file, int line, const char *str,
     msg += str;
     msg += "' in input script or data file";
     if (do_abort)
-      lmp->error->one(file,line,msg.c_str());
+      lmp->error->one(file,line,msg);
     else
-      lmp->error->all(file,line,msg.c_str());
+      lmp->error->all(file,line,msg);
   }
 
   return atof(str);
@@ -274,9 +274,9 @@ int utils::inumeric(const char *file, int line, const char *str,
     msg += str;
     msg += "' in input script or data file";
     if (do_abort)
-      lmp->error->one(file,line,msg.c_str());
+      lmp->error->one(file,line,msg);
     else
-      lmp->error->all(file,line,msg.c_str());
+      lmp->error->all(file,line,msg);
   }
 
   return atoi(str);
@@ -309,9 +309,9 @@ bigint utils::bnumeric(const char *file, int line, const char *str,
     msg += str;
     msg += "' in input script or data file";
     if (do_abort)
-      lmp->error->one(file,line,msg.c_str());
+      lmp->error->one(file,line,msg);
     else
-      lmp->error->all(file,line,msg.c_str());
+      lmp->error->all(file,line,msg);
   }
 
   return ATOBIGINT(str);
@@ -344,9 +344,9 @@ tagint utils::tnumeric(const char *file, int line, const char *str,
     msg += str;
     msg += "' in input script or data file";
     if (do_abort)
-      lmp->error->one(file,line,msg.c_str());
+      lmp->error->one(file,line,msg);
     else
-      lmp->error->all(file,line,msg.c_str());
+      lmp->error->all(file,line,msg);
   }
 
   return ATOTAGINT(str);