diff --git a/crypto/sha/asm/sha1-586.pl b/crypto/sha/asm/sha1-586.pl
index e0b5d83..04ccc9f 100644
--- a/crypto/sha/asm/sha1-586.pl
+++ b/crypto/sha/asm/sha1-586.pl
@@ -136,6 +136,10 @@
 
 $shaext=$xmm;	### set to zero if compiling for 1.0.1
 
+# TODO(davidben): Consider enabling the Intel SHA Extensions code once it's
+# been tested.
+$shaext = 0;
+
 &external_label("OPENSSL_ia32cap_P") if ($xmm);
 
 
diff --git a/crypto/sha/asm/sha1-x86_64.pl b/crypto/sha/asm/sha1-x86_64.pl
index 124034d..a53f0c2 100644
--- a/crypto/sha/asm/sha1-x86_64.pl
+++ b/crypto/sha/asm/sha1-x86_64.pl
@@ -111,6 +111,8 @@
 	$avx = ($2>=3.0) + ($2>3.0);
 }
 
+# TODO(davidben): Consider enabling the Intel SHA Extensions code once it's
+# been tested.
 $shaext=0;	### set to zero if compiling for 1.0.1
 $avx=1		if (!$shaext && $avx);
 
diff --git a/crypto/sha/asm/sha256-586.pl b/crypto/sha/asm/sha256-586.pl
index e907714..80867d2 100644
--- a/crypto/sha/asm/sha256-586.pl
+++ b/crypto/sha/asm/sha256-586.pl
@@ -89,6 +89,10 @@
 
 $shaext=$xmm;	### set to zero if compiling for 1.0.1
 
+# TODO(davidben): Consider enabling the Intel SHA Extensions code once it's
+# been tested.
+$shaext = 0;
+
 $unroll_after = 64*4;	# If pre-evicted from L1P cache first spin of
 			# fully unrolled loop was measured to run about
 			# 3-4x slower. If slowdown coefficient is N and
diff --git a/crypto/sha/asm/sha512-x86_64.pl b/crypto/sha/asm/sha512-x86_64.pl
index 653f7c0..a7da786 100644
--- a/crypto/sha/asm/sha512-x86_64.pl
+++ b/crypto/sha/asm/sha512-x86_64.pl
@@ -128,6 +128,8 @@
 	$avx = ($2>=3.0) + ($2>3.0);
 }
 
+# TODO(davidben): Consider enabling the Intel SHA Extensions code once it's
+# been tested.
 $shaext=0;	### set to zero if compiling for 1.0.1
 $avx=1		if (!$shaext && $avx);