diff --git a/ChangeLog b/ChangeLog
index b81f351ac2..a0c86149b0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Fri Jul 15 01:51:25 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* regint.h (PLATFORM_UNALIGNED_WORD_ACCESS): Power PC does not
+	  allow unaligned word access.
+
+	* st.c (UNALIGNED_WORD_ACCESS): x86_64 allows unaligned word
+	  access as well as i386.
+
 Thu Jul 14 12:19:34 2011  Hiroshi Nakamura  <nahi@ruby-lang.org>
 
 	* ext/openssl/ossl.c (ossl_verify_cb): trap the exception from
diff --git a/regint.h b/regint.h
index 631b2f471a..cd3c2a1035 100644
--- a/regint.h
+++ b/regint.h
@@ -48,7 +48,6 @@
 #endif
 
 #if defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
-    (defined(__ppc__) && defined(__APPLE__)) || \
     defined(__x86_64) || defined(__x86_64__) || defined(_M_AMD86) || \
     defined(__mc68020__)
 #define PLATFORM_UNALIGNED_WORD_ACCESS
diff --git a/st.c b/st.c
index ba21b31a5b..8394cc6b72 100644
--- a/st.c
+++ b/st.c
@@ -999,7 +999,9 @@ strhash(st_data_t arg)
 #else
 
 #ifndef UNALIGNED_WORD_ACCESS
-# if defined __i386__ || defined _M_IX86
+# if defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
+     defined(__x86_64) || defined(__x86_64__) || defined(_M_AMD86) || \
+     defined(__mc68020__)
 #   define UNALIGNED_WORD_ACCESS 1
 # endif
 #endif