diff --git a/acconfig.h b/acconfig.h
index cdb353e6630c467fb4680f28078e57ac2c914c24..df5fab92d65699c72585c0594002352dcdf08310 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -27,3 +27,9 @@
 
 /* Define if you have the gethostbyname_r() function with 6 arguments */
 #undef HAVE_GETHOSTBYNAME_R_6
+
+/* Define if you have the inet_ntoa_r function declared. */
+#undef HAVE_INET_NTOA_R_DECL
+
+/* Define if you need the _REENTRANT define for some functions */
+#undef NEED_REENTRANT
diff --git a/lib/getdate.y b/lib/getdate.y
index 5e1a763971f874a14a036eb22b0d66c88b6a703a..8c02832fe0317867cafe9591d883f1a2c341bb5b 100644
--- a/lib/getdate.y
+++ b/lib/getdate.y
@@ -8,15 +8,18 @@
 **  This code is in the public domain and has no copyright.
 */
 
-#define _REENTRANT /* Necessary to use in Solaris, since the silly guys at Sun
-                      made the localtime_r() prototype dependent on it (or
-                      _POSIX_C_SOURCE or _POSIX_PTHREAD_SEMANTICS). */
-
 #ifdef HAVE_CONFIG_H
 # include "config.h"
 # ifdef HAVE_ALLOCA_H
 #  include <alloca.h>
 # endif
+
+# ifdef NEED_REENTRANT
+# define _REENTRANT /* Necessary to use in Solaris, since the silly guys at
+                       Sun made the localtime_r() prototype dependent on it
+                       (or _POSIX_C_SOURCE or _POSIX_PTHREAD_SEMANTICS) */
+# endif
+
 # ifdef HAVE_TIME_H
 #  include <time.h>
 # endif