diff --git a/reactos/lib/crt/stdlib/witoa.c b/reactos/lib/crt/stdlib/witoa.c
index d9f414afb5e..a19630e2c69 100644
--- a/reactos/lib/crt/stdlib/witoa.c
+++ b/reactos/lib/crt/stdlib/witoa.c
@@ -13,49 +13,46 @@
 
 /*
  * @implemented
+ * copy _i64toa from wine cvs 2006 month 05 day 21
  */
 char* _i64toa(__int64 value, char* string, int radix)
 {
-  char tmp[65];
-  char *tp = tmp;
-  int i;
-  unsigned v;
-  int sign;
-  char *sp;
+    ULONGLONG val;
+    int negative;
+    char buffer[65];
+    char *pos;
+    int digit;
 
-  if (radix > 36 || radix <= 1)
-  {
-    __set_errno(EDOM);
-    return 0;
-  }
+    if (value < 0 && radix == 10) {
+	negative = 1;
+        val = -value;
+    } else {
+	negative = 0;
+        val = value;
+    } /* if */
 
-  sign = (radix == 10 && value < 0);
-  if (sign)
-    v = -value;
-  else
-    v = (unsigned)value;
-  while (v || tp == tmp)
-  {
-    i = v % radix;
-    v = v / radix;
-    if (i < 10)
-      *tp++ = i+'0';
-    else
-      *tp++ = i + 'a' - 10;
-  }
+    pos = &buffer[64];
+    *pos = '\0';
 
-  if (string == 0)
-    string = (char *)malloc((tp-tmp)+sign+1);
-  sp = string;
+    do {
+	digit = val % radix;
+	val = val / radix;
+	if (digit < 10) {
+	    *--pos = '0' + digit;
+	} else {
+	    *--pos = 'a' + digit - 10;
+	} /* if */
+    } while (val != 0L);
 
-  if (sign)
-    *sp++ = '-';
-  while (tp > tmp)
-    *sp++ = *--tp;
-  *sp = 0;
-  return string;
+    if (negative) {
+	*--pos = '-';
+    } /* if */
+
+    memcpy(string, pos, &buffer[64] - pos + 1);
+    return string;
 }
 
+
 /*
  * @implemented
  */
diff --git a/reactos/lib/string/itoa.c b/reactos/lib/string/itoa.c
index aed9a32ffd7..bf2e1ea0ca4 100644
--- a/reactos/lib/string/itoa.c
+++ b/reactos/lib/string/itoa.c
@@ -1,46 +1,47 @@
 #include <string.h>
 #include <stdlib.h>
+#include <windows.h>
 
 /*
  * @implemented
+ * copy _i64toa from wine cvs 2006 month 05 day 21
  */
 char *
 _i64toa(__int64 value, char *string, int radix)
 {
-  char tmp[65];
-  char *tp = tmp;
-  __int64 i;
-  unsigned __int64 v;
-  __int64 sign;
-  char *sp;
+    ULONGLONG  val;
+    int negative;
+    char buffer[65];
+    char *pos;
+    int digit;
 
-  if (radix > 36 || radix <= 1)
-  {
-    return 0;
-  }
+    if (value < 0 && radix == 10) {
+	negative = 1;
+        val = -value;
+    } else {
+	negative = 0;
+        val = value;
+    } /* if */
 
-  sign = (radix == 10 && value < 0);
-  if (sign)
-    v = -value;
-  else
-    v = (unsigned __int64)value;
-  while (v || tp == tmp)
-  {
-    i = v % radix;
-    v = v / radix;
-    if (i < 10)
-      *tp++ = i+'0';
-    else
-      *tp++ = i + 'a' - 10;
-  }
+    pos = &buffer[64];
+    *pos = '\0';
 
-  sp = string;
-  if (sign)
-    *sp++ = '-';
-  while (tp > tmp)
-    *sp++ = *--tp;
-  *sp = 0;
-  return string;
+    do {
+	digit = val % radix;
+	val = val / radix;
+	if (digit < 10) {
+	    *--pos = '0' + digit;
+	} else {
+	    *--pos = 'a' + digit - 10;
+	} /* if */
+    } while (val != 0L);
+
+    if (negative) {
+	*--pos = '-';
+    } /* if */
+
+    memcpy(string, pos, &buffer[64] - pos + 1);
+    return string;
 }