diff --git a/include/bitcoin/system/intrinsics/haves.hpp b/include/bitcoin/system/intrinsics/haves.hpp
index 908f1aecd1..dfa2e6fc0b 100644
--- a/include/bitcoin/system/intrinsics/haves.hpp
+++ b/include/bitcoin/system/intrinsics/haves.hpp
@@ -32,7 +32,7 @@ namespace system {
 
 // HACK: work around vectorizations failing on non-xcode clang.
 #if defined(HAVE_CLANG) && !defined(HAVE_XCODE)
-    constexpr auto with_clang = true;
+    constexpr auto with_clang = false;
 #else
     constexpr auto with_clang = false;
 #endif