diff --git a/ChangeLog b/ChangeLog
index 8bebfd0aaa..96ebd5afe9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jul 16 11:38:21 2015  Eric Wong  <e@80x24.org>
+
+	* process.c (close_unless_reserved): declare type of `fd' arg
+
 Thu Jul 16 08:47:29 2015  Eric Wong  <e@80x24.org>
 
 	* load.c (rb_construct_expanded_load_path): fstring expanded path
diff --git a/process.c b/process.c
index ac724639f9..708cea91ce 100644
--- a/process.c
+++ b/process.c
@@ -294,7 +294,8 @@ extern ID ruby_static_id_status;
 #define ALWAYS_NEED_ENVP 0
 #endif
 
-static inline int close_unless_reserved(fd)
+static inline int
+close_unless_reserved(int fd)
 {
     /* Do nothing to the reserved fd because it should be closed in exec(2)
        due to the O_CLOEXEC or FD_CLOEXEC flag. */