--- a/lib/regex_internal.h
+++ b/lib/regex_internal.h
@@ -39,6 +39,14 @@
 #include <intprops.h>
 #include <verify.h>
 
+#ifndef __LONG_WIDTH__
+#if LONG_WIDTH
+#define __LONG_WIDTH__ LONG_WIDTH
+#else
+#define __LONG_WIDTH__ __WORDSIZE
+#endif
+#endif
+
 #if defined DEBUG && DEBUG != 0
 # include <assert.h>
 # define DEBUG_ASSERT(x) assert (x)