diff --git a/ChangeLog b/ChangeLog
index 4cb884c1aa..d69317e3a9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Nov 22 00:25:17 2011  Tanaka Akira  <akr@fsij.org>
+
+	* io.c (linux_get_maxfd): get rid of a warning.
+
 Mon Nov 21 23:39:14 2011  Tanaka Akira  <akr@fsij.org>
 
 	* io.c (linux_get_maxfd): new function to find maximum fd on Linux.
diff --git a/io.c b/io.c
index 47ce2bac89..81da283384 100644
--- a/io.c
+++ b/io.c
@@ -5153,7 +5153,7 @@ linux_get_maxfd(void)
     if (ss == -1) goto err;
     p = buf;
     e = buf + ss;
-    while (sizeof("FDSize:\t0\n")-1 <= e-p &&
+    while ((int)sizeof("FDSize:\t0\n")-1 <= e-p &&
            (n = memchr(p, '\n', e-p)) != NULL) {
         if (memcmp(p, "FDSize:", sizeof("FDSize:")-1) == 0) {
             int fdsize;