diff --git a/lib/mes/ntoab.c b/lib/mes/ntoab.c
index f2f0e89d..988a0b25 100644
--- a/lib/mes/ntoab.c
+++ b/lib/mes/ntoab.c
@@ -18,24 +18,32 @@
  * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <assert.h>
 #include <mes/lib.h>
-#include <stdint.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
 
-#define STR(x) #x
-#define XSTR(s) STR(s)
+char *__itoa_buf;
 
 char *
 ntoab (long x, unsigned base, int signed_p)
 {
-  static char itoa_buf[20];
-  char *p = itoa_buf + 11;
-  *p-- = 0;
-  assert(base > 1);
+#if 0
+  if (! __itoa_buf)
+    __itoa_buf = malloc (20);
+  p = __itoa_buf + 11;
+#else
+  static char buf[20];
+  char *p = buf + 19;
+#endif
+
+  p[0] = 0;
+  p = p - 1;
+  assert_msg (base > 0, "base > 0");
 
   int sign_p = 0;
   unsigned long u;
-  if (signed_p && x < 0)
+  if (signed_p != 0 && x < 0)
     {
       sign_p = 1;
       /* Avoid LONG_MIN */
@@ -54,12 +62,19 @@ ntoab (long x, unsigned base, int signed_p)
       i = u % base;
       u = u / base;
 #endif
-      *p-- = i > 9 ? 'a' + i - 10 : '0' + i;
+      if (i > 9)
+        p[0] = 'a' + i - 10;
+      else
+        p[0] = '0' + i;
+      p = p - 1;
     }
-  while (u);
+  while (u != 0);
 
-  if (sign_p && *(p + 1) != '0')
-    *p-- = '-';
+  if (sign_p && p[1] != '0')
+    {
+      p[0] = '-';
+      p = p - 1;
+    }
 
   return p + 1;
 }