diff --git a/sha3/xor.go b/sha3/xor.go
index d622979..30711f1 100644
--- a/sha3/xor.go
+++ b/sha3/xor.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !amd64,!386 appengine
+// +build !amd64,!386,!ppc64,!ppc64le appengine
 
 package sha3
 
diff --git a/sha3/xor_unaligned.go b/sha3/xor_unaligned.go
index c7851a1..ca07a72 100644
--- a/sha3/xor_unaligned.go
+++ b/sha3/xor_unaligned.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build amd64 386
+// +build amd64 386 ppc64 ppc64le
 // +build !appengine
 
 package sha3