diff --git a/config.h.in b/config.h.in
index 571bc4d..76691ac 100644
--- a/config.h.in
+++ b/config.h.in
@@ -101,6 +101,9 @@
    (e.g. void fprintf(FILE *, char *, ...);) *and* <stdarg.h> */
 #undef HAVE_STDARG_PROTOTYPES
 
+/* Define if you have POSIX threads */
+#undef _POSIX_THREADS
+
 /* Define to empty if the keyword does not work.  */
 #undef signed
 
@@ -258,6 +261,9 @@
 /* Define if you have the nsl library (-lnsl).  */
 #undef HAVE_LIBNSL
 
+/* Define if you have the pthreads library (-lpthreads).  */
+#undef HAVE_LIBPTHREADS
+
 /* Define if you have the seq library (-lseq).  */
 #undef HAVE_LIBSEQ