diff --git a/configure.ac b/configure.ac
index d50e2bb2..77934a7e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -390,6 +390,7 @@ fi
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
 AC_TYPE_SIZE_T
+AC_TYPE_MODE_T
 AC_HEADER_TIME
 AC_STRUCT_TM