diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 78a9f7fa0725..ebfdd3658d12 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,7 @@
 2018-06-04  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/bits/postypes.h (fpos): Define special members as defaulted.
+
 	PR libstdc++/85930
 	* include/bits/shared_ptr_base.h (_Sp_make_shared_tag::_S_ti): Align
 	the static variable correctly.
diff --git a/libstdc++-v3/include/bits/postypes.h b/libstdc++-v3/include/bits/postypes.h
index ba7c54781e8d..8abdbf023225 100644
--- a/libstdc++-v3/include/bits/postypes.h
+++ b/libstdc++-v3/include/bits/postypes.h
@@ -133,6 +133,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       fpos(streamoff __off)
       : _M_off(__off), _M_state() { }
 
+#if __cplusplus >= 201103L
+      fpos(const fpos&) = default;
+      fpos& operator=(const fpos&) = default;
+      ~fpos() = default;
+#endif
+
       /// Convert to streamoff.
       operator streamoff() const { return _M_off; }