diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 67643de3ef6..9add722014e 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2011-09-24  John Salmon  <john.salmon@deshaw.com>
+
+	PR libstdc++/50510
+	* include/bits/random.tcc (seed_seq::generate): Fix computation.
+
 2011-09-24  John Salmon  <john.salmon@deshaw.com>
 
 	PR libstdc++/50509
diff --git a/libstdc++-v3/include/bits/random.tcc b/libstdc++-v3/include/bits/random.tcc
index d35f2f4cf9a..0e74848ff3c 100644
--- a/libstdc++-v3/include/bits/random.tcc
+++ b/libstdc++-v3/include/bits/random.tcc
@@ -2796,8 +2796,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  _Type __r4 = __r3 - __k % __n;
 	  __r4 = __detail::__mod<_Type,
 	           __detail::_Shift<_Type, 32>::__value>(__r4);
-	  __begin[(__k + __p) % __n] ^= __r4;
-	  __begin[(__k + __q) % __n] ^= __r3;
+	  __begin[(__k + __p) % __n] ^= __r3;
+	  __begin[(__k + __q) % __n] ^= __r4;
 	  __begin[__k % __n] = __r4;
 	}
     }