diff --git a/ChangeLog b/ChangeLog
index 1a5763c..795ff06 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2014-02-18  Niibe Yutaka  <gniibe@fsij.org>
 
+	* src/sha256.c (memcpy_output_bswap32): Bug fix.
+
 	* src/modp256k1.h, src/modp256k1.c: New.
 
 2014-02-17  Niibe Yutaka  <gniibe@fsij.org>
diff --git a/src/sha256.c b/src/sha256.c
index 7267014..a44e22e 100644
--- a/src/sha256.c
+++ b/src/sha256.c
@@ -55,12 +55,12 @@
 static void memcpy_output_bswap32 (unsigned char *dst, const uint32_t *p)
 {
   int i;
-  uint32_t q;
+  uint32_t q = 0;
 
   for (i = 0; i < 32; i++)
     {
       if ((i & 3) == 0)
-	q[i] = __builtin_bswap32 (p[i >> 2]); /* bswap32 is GCC extention */
+	q = __builtin_bswap32 (p[i >> 2]); /* bswap32 is GCC extention */
       dst[i] = q >> ((i & 3) * 8);
     }
 }