diff --git a/src/tool_paramhlp.c b/src/tool_paramhlp.c
index adb12ce70..2d8e7f0d6 100644
--- a/src/tool_paramhlp.c
+++ b/src/tool_paramhlp.c
@@ -151,8 +151,6 @@ void cleanarg(char *str)
  * Parse the string and write the integer in the given address. Return
  * non-zero on failure, zero on success.
  *
- * The string must start with a digit to be valid.
- *
  * Since this function gets called with the 'nextarg' pointer from within the
  * getparameter a lot, we must check it for NULL before accessing the str
  * data.
@@ -160,7 +158,7 @@ void cleanarg(char *str)
 
 int str2num(long *val, const char *str)
 {
-  if(str && ISDIGIT(*str)) {
+  if(str) {
     char *endptr;
     long num = strtol(str, &endptr, 10);
     if((endptr != str) && (endptr == str + strlen(str))) {