diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ebe29e61fa8..e365a56be68 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2018-06-26  Aaron Sawdey  <acsawdey@linux.ibm.com>
+
+	* config/rs6000/rs6000-string.c (expand_block_clear): Don't use
+	unaligned vsx for 16B memset.
+
 2018-06-26  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	PR target/86285
diff --git a/gcc/config/rs6000/rs6000-string.c b/gcc/config/rs6000/rs6000-string.c
index 7e49568a1ed..f9dd54eb639 100644
--- a/gcc/config/rs6000/rs6000-string.c
+++ b/gcc/config/rs6000/rs6000-string.c
@@ -90,7 +90,9 @@ expand_block_clear (rtx operands[])
       machine_mode mode = BLKmode;
       rtx dest;
 
-      if (bytes >= 16 && TARGET_ALTIVEC && (align >= 128 || TARGET_EFFICIENT_UNALIGNED_VSX))
+      if (TARGET_ALTIVEC
+	  && ((bytes >= 16 && align >= 128)
+	      || (bytes >= 32 && TARGET_EFFICIENT_UNALIGNED_VSX)))
 	{
 	  clear_bytes = 16;
 	  mode = V4SImode;