diff --git a/src/frontend/inpc_probe.c b/src/frontend/inpc_probe.c
index 74a759e07..42ecf871c 100644
--- a/src/frontend/inpc_probe.c
+++ b/src/frontend/inpc_probe.c
@@ -1242,7 +1242,7 @@ static int setallvsources(struct card *tmpcard, NGHASHPTR instances, char *instn
         sadd(&BVrefline, "Vref ");
         sadd(&BVrefline, instname);
         sadd(&BVrefline, "Vref 0 V = 1/");
-        sadd(&BVrefline, _itoa(numnodes, numbuf, 10));
+        sadd(&BVrefline, itoa10(numnodes, numbuf));
         sadd(&BVrefline, "*(");
         /* For example: Bq1power q1:power 0 V = */
         cadd(&Bpowerline, 'B');
@@ -1278,7 +1278,7 @@ static int setallvsources(struct card *tmpcard, NGHASHPTR instances, char *instn
         char* strnode1 = gettok(&instline);
         char* newnode = tprintf("int_%s_%s_%d", strnode1, instname, nodenum);
         char nodenumstr[3];
-        char *nodename1 = get_terminal_name(instname, _itoa(nodenum, nodenumstr, 10), instances);
+        char *nodename1 = get_terminal_name(instname, itoa10(nodenum, nodenumstr), instances);
 
         newline = tprintf("%s %s %s", begstr, newnode, instline);
 
diff --git a/src/include/ngspice/stringutil.h b/src/include/ngspice/stringutil.h
index 3ee188ab8..a78cb558e 100644
--- a/src/include/ngspice/stringutil.h
+++ b/src/include/ngspice/stringutil.h
@@ -75,7 +75,7 @@ int substring_n(size_t n_char_pattern, const char *p_pattern,
         size_t n_char_str, const char *p_str);
 char *tprintf(const char *fmt, ...) ATTR_TPRINTF;
 char *tvprintf(const char *fmt, va_list args);
-
+char* itoa10(int val, char* buf);
 
 
 /* Allocate and create a copy of a string if the argument is not null or
diff --git a/src/misc/string.c b/src/misc/string.c
index b9dfa3f7b..4001c1335 100644
--- a/src/misc/string.c
+++ b/src/misc/string.c
@@ -1403,3 +1403,29 @@ bool has_escape_or_quote(size_t n, const char *str)
     return FALSE;
 } /* end of function may_have_eq */
 
+/* Converts integer to string.
+   Return the result string.
+   Only 10 radix is supported */
+char *itoa10(int n, char s[])
+{
+    int i, j, sign;
+    char c;
+
+    if ((sign = n) < 0)  /* record sign */
+        n = -n;          /* make n positive */
+    i = 0;
+    do {       /* generate digits in reverse order */
+        s[i++] = n % 10 + '0';   /* get next digit */
+    } while ((n /= 10) > 0);     /* delete it */
+    if (sign < 0)
+        s[i++] = '-';
+    s[i] = '\0';
+    /* revert string */
+    for (i = 0, j = (int)strlen(s) - 1; i < j; i++, j--) {
+        c = s[i];
+        s[i] = s[j];
+        s[j] = c;
+    }
+    return s;
+}
+