Index: compiler-rt/lib/ubsan/ubsan_platform.h
--- compiler-rt/lib/ubsan/ubsan_platform.h.orig
+++ compiler-rt/lib/ubsan/ubsan_platform.h
@@ -14,7 +14,7 @@
 
 // Other platforms should be easy to add, and probably work as-is.
 #if defined(__linux__) || defined(__FreeBSD__) || defined(__APPLE__) ||        \
-    defined(__NetBSD__) || defined(__DragonFly__) ||                           \
+    defined(__NetBSD__) || defined(__DragonFly__) || defined(__OpenBSD__) ||   \
     (defined(__sun__) && defined(__svr4__)) || defined(_WIN32) ||              \
     defined(__Fuchsia__) || defined(__HAIKU__)
 #define CAN_SANITIZE_UB 1
