diff --git a/c/src/ChangeLog b/c/src/ChangeLog
index 6f0a1bf39d..343fc36db1 100644
--- a/c/src/ChangeLog
+++ b/c/src/ChangeLog
@@ -1,3 +1,7 @@
+2010-03-11	Joel Sherrill <joel.sherrill@oarcorp.com>
+
+	* libchip/network/i82586.c: Fix warnings for ctype methods.
+
 2010-02-19	Chris Johns <chrisj@rtems.org>
 
 	* libchip/ide/ide_controller.c: Create the devices as block
diff --git a/c/src/libchip/network/i82586.c b/c/src/libchip/network/i82586.c
index 7ec9dbb438..9a09d0284b 100644
--- a/c/src/libchip/network/i82586.c
+++ b/c/src/libchip/network/i82586.c
@@ -246,7 +246,7 @@ char *bitmask_snprintf(unsigned long value, const char *format, char *buf, int b
   while (*format)
   {
     if (value & 0x80000000)
-      while (isalnum(*format))
+      while (isalnum((int)*format))
         *b++ = *format;
     else
       *b++ = '0';