Add forgotten endif
diff --git a/highwayhash/arch_specific.cc b/highwayhash/arch_specific.cc
index b3ec119..82d1574 100644
--- a/highwayhash/arch_specific.cc
+++ b/highwayhash/arch_specific.cc
@@ -27,6 +27,7 @@
 #include <sys/types.h>
 #include <sys/sysctl.h>
 #endif
+#endif
 
 #include <string.h>  // memcpy
 #include <string>