diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ea88034c982..0c5786b1f96 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2017-11-07  Jonathan Wakely  <jwakely@redhat.com>
+
+	* src/filesystem/ops-common.h (make_file_type) [S_ISSOCK]: Only use
+	S_ISSOCK when defined.
+
 2017-11-06  François Dumont  <fdumont@gcc.gnu.org>
 
 	* testsuite/libstdc++-prettyprinters/tr1.cc:  Compile with -O0.
diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
index 12c12b08f8c..f96a999264f 100644
--- a/libstdc++-v3/src/filesystem/ops-common.h
+++ b/libstdc++-v3/src/filesystem/ops-common.h
@@ -113,8 +113,10 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
       return file_type::fifo;
     else if (S_ISLNK(st.st_mode))
       return file_type::symlink;
+#ifdef S_ISSOCK // not present until POSIX:2001
     else if (S_ISSOCK(st.st_mode))
       return file_type::socket;
+#endif
 #endif
     return file_type::unknown;
   }