diff --git a/gfan.spec b/gfan.spec
index 5cfbb1b..70fb6ad 100644
--- a/gfan.spec
+++ b/gfan.spec
@@ -58,7 +58,7 @@ varieties. These are polyhedral fans associated to polynomial ideals.
 
 %build
 autoreconf -fi
-export CXXFLAGS="%optflags -Wno-sign-compare -Wno-reorder -Wno-unused -Wno-comment -Wno-misleading-indentation"
+export CXXFLAGS="%optflags -Wno-sign-compare -Wno-reorder -Wno-unused -Wno-comment -Wno-misleading-indentation -std=gnu++11"
 %configure
 make %{?_smp_mflags} V=1
 %if 0%{?with_pdf}