diff --git a/nix/bootstrap.nix b/nix/bootstrap.nix
index d89bd454b3..9232145183 100644
--- a/nix/bootstrap.nix
+++ b/nix/bootstrap.nix
@@ -15,7 +15,7 @@ rec {
     '';
   } // args // {
     src = args.realSrc or (lib.sourceByRegex args.src [ "[a-z].*" "CMakeLists\.txt" ]);
-    cmakeFlags = (args.cmakeFlags or [ "-DSTAGE=1" "-DPREV_STAGE=./faux-prev-stage" "-DUSE_GITHASH=OFF" ]) ++ extraCMakeFlags ++ lib.optional (args.debug or debug) [ "-DCMAKE_BUILD_TYPE=Debug" ];
+    cmakeFlags = (args.cmakeFlags or [ "-DSTAGE=1" "-DPREV_STAGE=./faux-prev-stage" "-DUSE_GITHASH=OFF" ]) ++ (args.extraCMakeFlags or extraCMakeFlags) ++ lib.optional (args.debug or debug) [ "-DCMAKE_BUILD_TYPE=Debug" ];
   });
   lean-bin-tools-unwrapped = buildCMake {
     name = "lean-bin-tools";
@@ -56,6 +56,7 @@ rec {
     src = ../stage0/src;
     debug = stage0debug;
     cmakeFlags = [ "-DSTAGE=0" ];
+    extraCMakeFlags = [];
     preConfigure = ''
       ln -s ${../stage0/stdlib} ../stdlib
     '';