diff --git a/src/autoconf.h.in b/src/autoconf.h.in
index 3ea96d74..069e6452 100644
--- a/src/autoconf.h.in
+++ b/src/autoconf.h.in
@@ -20,7 +20,6 @@
 #undef HAVE_FCNTL_H
 
 /* Define to 1 if you have the `fdopen' function. */
-#undef HAVE_FDOPEN
 
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
