diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 3542cd136..43fedbbd5 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+2011-06-15  Christopher Faylor  <me.cygwin2011@cgf.cx>
+
+	* errno.cc (EIO): Lowercase "o" representative string.
+
 2011-06-14  Christopher Faylor  <me.cygwin2011@cgf.cx>
 
 	* cygheap.h (init_cygheap::ctty_on_hold): Remove conditionalized
diff --git a/winsup/cygwin/errno.cc b/winsup/cygwin/errno.cc
index b775db50d..c936ccde9 100644
--- a/winsup/cygwin/errno.cc
+++ b/winsup/cygwin/errno.cc
@@ -167,7 +167,7 @@ const char *_sys_errlist[] NO_COPY_INIT =
 /* ENOENT 2 */		  "No such file or directory",
 /* ESRCH 3 */		  "No such process",
 /* EINTR 4 */		  "Interrupted system call",
-/* EIO 5 */		  "Input/Output error",
+/* EIO 5 */		  "Input/output error",
 /* ENXIO 6 */		  "No such device or address",
 /* E2BIG 7 */		  "Argument list too long",
 /* ENOEXEC 8 */		  "Exec format error",