diff --git a/include/jemalloc/internal/util.h b/include/jemalloc/internal/util.h
index 24f23629..b400f231 100644
--- a/include/jemalloc/internal/util.h
+++ b/include/jemalloc/internal/util.h
@@ -39,12 +39,6 @@
 #  define unlikely(x) !!(x)
 #endif
 
-#if !defined(JEMALLOC_INTERNAL_UNREACHABLE)
-#  error JEMALLOC_INTERNAL_UNREACHABLE should have been defined by configure
-#endif
-
-#define unreachable() JEMALLOC_INTERNAL_UNREACHABLE()
-
 /* Set error code. */
 UTIL_INLINE void
 set_errno(int errnum) {