diff --git a/acconfig.h b/acconfig.h
index 14bf222..18d4a2b 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -35,6 +35,9 @@
    (e.g. void fprintf(FILE *, char *, ...);) *and* <stdarg.h> */
 #undef HAVE_STDARG_PROTOTYPES
 
+/* Define if malloc(0) returns a NULL pointer */
+#undef MALLOC_ZERO_RETURNS_NULL
+
 /* Define if you have POSIX threads */
 #undef _POSIX_THREADS
 
diff --git a/config.h.in b/config.h.in
index 40d3608..adae370 100644
--- a/config.h.in
+++ b/config.h.in
@@ -96,6 +96,9 @@
    (e.g. void fprintf(FILE *, char *, ...);) *and* <stdarg.h> */
 #undef HAVE_STDARG_PROTOTYPES
 
+/* Define if malloc(0) returns a NULL pointer */
+#undef MALLOC_ZERO_RETURNS_NULL
+
 /* Define if you have POSIX threads */
 #undef _POSIX_THREADS