diff --git a/nix/overlay.nix b/nix/overlay.nix
index df86028545..3b903b04b2 100644
--- a/nix/overlay.nix
+++ b/nix/overlay.nix
@@ -121,7 +121,6 @@ pkgs: prevPkgs: {
             make -j$NIX_BUILD_CORES
             make install
           '';
-          env.CXXFLAGS = "--std=c++14"; # gcc 9 doesn't seem to like C++17
         };
 
       # binutils -- binutils with the wrappers provided by nixpkgs