diff --git a/ChangeLog b/ChangeLog
index 5450d5567f..84f24c1c08 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu May 13 21:40:39 2010  Tanaka Akira  <akr@fsij.org>
+
+	* missing/ffs.c (ffs): fixed for non-zero values.
+
 Thu May 13 18:45:25 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/io/console/console.c (get_write_fd): return primary fd if no
diff --git a/missing/ffs.c b/missing/ffs.c
index 1a1189968a..bad99cf116 100644
--- a/missing/ffs.c
+++ b/missing/ffs.c
@@ -6,11 +6,13 @@
 int ffs(int arg)
 {
     unsigned int x = (unsigned int)arg;
-    int r = 0;
+    int r;
 
     if (x == 0)
         return 0;
 
+    r = 1;
+
 #if 32 < SIZEOF_INT * CHAR_BIT
     if ((x & 0xffffffff) == 0) {
         x >>= 32;