diff --git a/Generators/GeneratorUtils/test/StringParse_test.cxx b/Generators/GeneratorUtils/test/StringParse_test.cxx
index 1c4ee03e825556b134733203e7295974bd2080bf..d31a8d589c6f7c4ba216dbbca85c737522555333 100644
--- a/Generators/GeneratorUtils/test/StringParse_test.cxx
+++ b/Generators/GeneratorUtils/test/StringParse_test.cxx
@@ -2,7 +2,17 @@
   Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
 */
 
+// Suppress a gcc8 warning from boost.
+// (Binaries apparently include boost with -I rather than -isystem.)
+// Fixed in boost 1.68 (see https://github.com/boostorg/mpl/issues/31)
+#ifdef __GNUC__
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wparentheses"
+#endif
 #include "GeneratorUtils/StringParse.h"
+#ifdef __GNUC__
+# pragma GCC diagnostic pop
+#endif
 #include <iostream>
 #include <cmath>