diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index aa661b963..eeb3edde9 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,8 @@
+2010-04-06  Corinna Vinschen  <corinna@vinschen.de>
+
+	* libc/stdlib/btowc.c (btowc): Reorganize EOF check.  Fix incorrect
+	return value if input byte is ASCII NUL.
+
 2010-04-01  Joel Sherrill <joel.sherrill@oarcorp.com>
 
 	* libc/include/sched.h: Include prototypes for
diff --git a/newlib/libc/stdlib/btowc.c b/newlib/libc/stdlib/btowc.c
index f5ef4624a..ec6c29152 100644
--- a/newlib/libc/stdlib/btowc.c
+++ b/newlib/libc/stdlib/btowc.c
@@ -13,6 +13,9 @@ btowc (int c)
   wchar_t pwc;
   unsigned char b;
 
+  if (c == EOF)
+    return WEOF;
+
   b = (unsigned char)c;
 
   /* Put mbs in initial state. */
@@ -22,8 +25,8 @@ btowc (int c)
 
   retval = __mbtowc (_REENT, &pwc, &b, 1, __locale_charset (), &mbs);
 
-  if (c == EOF || retval != 1)
+  if (retval != 0 && retval != 1)
     return WEOF;
-  else
-    return (wint_t)pwc;
+
+  return (wint_t)pwc;
 }