Index: modcargo-crates/v8-0.74.3/third_party/zlib/BUILD.gn
--- modcargo-crates/v8-0.74.3/third_party/zlib/BUILD.gn.orig
+++ modcargo-crates/v8-0.74.3/third_party/zlib/BUILD.gn
@@ -121,6 +121,8 @@ if (use_arm_neon_optimizations) {
       defines = [ "CRC32_ARMV8_CRC32" ]
       if (is_android) {
         defines += [ "ARMV8_OS_ANDROID" ]
+      } else if (is_bsd) {
+        defines += [ "ARMV8_OS_OPENBSD" ]
       } else if (is_linux || is_chromeos) {
         defines += [ "ARMV8_OS_LINUX" ]
       } else if (is_mac) {
