diff --git a/doc/src/Errors_common.txt b/doc/src/Errors_common.txt
index 651040ebc9..da90aad64b 100644
--- a/doc/src/Errors_common.txt
+++ b/doc/src/Errors_common.txt
@@ -74,7 +74,7 @@ is an integer or floating-point number, respectively, and reject the
 input with an error message (for instance, when an integer is required,
 but a floating-point number 1.0 is provided):
 
-ERROR: Expected integer parameter in input script or data file :pre
+ERROR: Expected integer parameter instead of '1.0' in input script or data file :pre
 
 Some commands allow for using variable references in place of numeric
 constants so that the value can be evaluated and may change over the
@@ -85,6 +85,9 @@ reading the input and before parsing commands,
 
 NOTE: Using a variable reference (i.e. {v_name}) is only allowed if
 the documentation of the corresponding command explicitly says it is.
+Otherwise, you will receive an error message of this kind:
+
+ERROR: Expected floating point parameter instead of 'v_name' in input script or data file :pre
 
 Generally, LAMMPS will print a message to the screen and logfile and
 exit gracefully when it encounters a fatal error.  Sometimes it will
diff --git a/src/force.cpp b/src/force.cpp
index 2bfd809451..567cf2c9c5 100644
--- a/src/force.cpp
+++ b/src/force.cpp
@@ -934,20 +934,21 @@ void Force::boundsbig(const char *file, int line, char *str,
 
 double Force::numeric(const char *file, int line, char *str)
 {
-  if (!str)
-    error->all(file,line,"Expected floating point parameter "
-               "in input script or data file");
-  int n = strlen(str);
+  int n = 0;
+
+  if (str) n = strlen(str);
   if (n == 0)
-    error->all(file,line,"Expected floating point parameter "
-               "in input script or data file");
+    error->all(file,line,"Expected floating point parameter instead of"
+               " NULL or empty string in input script or data file");
 
   for (int i = 0; i < n; i++) {
     if (isdigit(str[i])) continue;
     if (str[i] == '-' || str[i] == '+' || str[i] == '.') continue;
     if (str[i] == 'e' || str[i] == 'E') continue;
-    error->all(file,line,"Expected floating point parameter "
-               "in input script or data file");
+    char msg[256];
+    snprintf(msg,256,"Expected floating point parameter instead of "
+                    "'%s' in input script or data file",str);
+    error->all(file,line,msg);
   }
 
   return atof(str);
@@ -961,18 +962,19 @@ double Force::numeric(const char *file, int line, char *str)
 
 int Force::inumeric(const char *file, int line, char *str)
 {
-  if (!str)
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
-  int n = strlen(str);
+  int n = 0;
+
+  if (str) n = strlen(str);
   if (n == 0)
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
+    error->all(file,line,"Expected integer parameter instead of "
+               "NULL or empty string in input script or data file");
 
   for (int i = 0; i < n; i++) {
     if (isdigit(str[i]) || str[i] == '-' || str[i] == '+') continue;
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
+    char msg[256];
+    snprintf(msg,256,"Expected integer parameter instead of "
+                    "'%s' in input script or data file",str);
+    error->all(file,line,msg);
   }
 
   return atoi(str);
@@ -986,18 +988,19 @@ int Force::inumeric(const char *file, int line, char *str)
 
 bigint Force::bnumeric(const char *file, int line, char *str)
 {
-  if (!str)
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
-  int n = strlen(str);
+  int n = 0;
+
+  if (str) n = strlen(str);
   if (n == 0)
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
+    error->all(file,line,"Expected integer parameter instead of "
+               "NULL or empty string in input script or data file");
 
   for (int i = 0; i < n; i++) {
     if (isdigit(str[i]) || str[i] == '-' || str[i] == '+') continue;
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
+    char msg[256];
+    snprintf(msg,256,"Expected integer parameter instead of "
+                    "'%s' in input script or data file",str);
+    error->all(file,line,msg);
   }
 
   return ATOBIGINT(str);
@@ -1011,18 +1014,19 @@ bigint Force::bnumeric(const char *file, int line, char *str)
 
 tagint Force::tnumeric(const char *file, int line, char *str)
 {
-  if (!str)
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
-  int n = strlen(str);
+  int n = 0;
+
+  if (str) n = strlen(str);
   if (n == 0)
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
+    error->all(file,line,"Expected integer parameter instead of "
+               "NULL or empty string in input script or data file");
 
   for (int i = 0; i < n; i++) {
     if (isdigit(str[i]) || str[i] == '-' || str[i] == '+') continue;
-    error->all(file,line,
-               "Expected integer parameter in input script or data file");
+    char msg[256];
+    snprintf(msg,256,"Expected integer parameter instead of "
+                    "'%s' in input script or data file",str);
+    error->all(file,line,msg);
   }
 
   return ATOTAGINT(str);