diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 7b6b807114a42ddce98d11d657c1c3d0e3d7fcd2..a93252076b97651a3306ce4914c7c68753c7b311 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -4744,7 +4744,7 @@ dnl
       [glibcxx_cv_fdopendir=yes],
       [glibcxx_cv_fdopendir=no])
   ])
-  if test $glibcxx_cv_truncate = yes; then
+  if test $glibcxx_cv_fdopendir = yes; then
     AC_DEFINE(HAVE_FDOPENDIR, 1, [Define if fdopendir is available in <dirent.h>.])
   fi
 dnl
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 5c6e51f5c11266ef60c7b7b9924abde6c9fb70e6..2b2f85782b1c80643033e6d8689c418eac408300 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -77080,7 +77080,7 @@ fi
 fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_fdopendir" >&5
 $as_echo "$glibcxx_cv_fdopendir" >&6; }
-  if test $glibcxx_cv_truncate = yes; then
+  if test $glibcxx_cv_fdopendir = yes; then
 
 $as_echo "#define HAVE_FDOPENDIR 1" >>confdefs.h