diff --git a/nix/default.nix b/nix/default.nix
index b16cebaf..660d7cc3 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -16,7 +16,7 @@ let
   src = gitignoreSource ./..;
 in
 {
-  inherit pkgs src;
+  inherit pkgs src sbt;
 
   clang = pkgs.clang_10;
 
diff --git a/scala-native.nix b/scala-native.nix
index ab4a89e6..f7e9eac2 100644
--- a/scala-native.nix
+++ b/scala-native.nix
@@ -1,7 +1,11 @@
 { project ? import ./nix { }
 }:
 
-project.pkgs.stdenv.mkDerivation rec {
+let
+  stdenv = project.pkgs.stdenvNoCC;
+in
+
+stdenv.mkDerivation rec {
   pname = "scala-native";
   version = "0.4.1-SNAPSHOT";
 
@@ -16,18 +20,18 @@ project.pkgs.stdenv.mkDerivation rec {
     let
       name = "${pname}-${version}";
     in
-    project.pkgs.stdenv.mkDerivation {
+    stdenv.mkDerivation {
       inherit src;
 
       name = "${name}-scala-native";
 
-      patches = [ ./toClass.diff ];
+      patches = [ ./toClass.diff ./stableNirOutput.diff ];
 
-      nativeBuildInputs = [ project.pkgs.sbt ];
+      nativeBuildInputs = [ project.sbt ];
 
       dontStrip = true;
       outputHashAlgo = "sha256";
-      outputHash = "1s1ki5jmh6r5d50ma8d032xgmvhmy2gv9aw4142ybc3ggfwbi3mk";
+      outputHash = "0m9jchavxxpsl1jg6gjsxbmybrq8lp44lyab6fki8w282386hqhy";
       outputHashMode = "recursive";
 
       preHook = ''
@@ -52,6 +56,8 @@ project.pkgs.stdenv.mkDerivation rec {
       buildPhase = ''
         runHook preBuild
 
+        export SCALANATIVE_MODE=release-fast
+
         sbt --sbt-dir "$HOME/sbt" --ivy "$HOME/.ivy2" --batch publishLocal '++2.13.6' \
             auxlib/publishLocal \
             clib/publishLocal \
diff --git a/shell.nix b/shell.nix
index 94b1460f..3c4c517b 100644
--- a/shell.nix
+++ b/shell.nix
@@ -2,12 +2,14 @@
 }:
 let
   scala-native = import ./scala-native.nix { inherit project; };
+  mkShell = project.pkgs.mkShell.override { stdenv = project.pkgs.stdenvNoCC; };
 in
-project.pkgs.mkShell {
+mkShell {
   CLANG_PATH = project.clang + "/bin/clang";
   CLANGPP_PATH = project.clang + "/bin/clang++";
 
-  buildInputs = builtins.attrValues project.devTools;
+  nativeBuildInputs = builtins.attrValues project.devTools;
+
   shellHook = ''
     ${project.ci.pre-commit-check.shellHook}
     mkdir --parents "$HOME/.ivy2/local"
diff --git a/stableNirOutput.diff b/stableNirOutput.diff
new file mode 100644
index 00000000..3a7456c8
--- /dev/null
+++ b/stableNirOutput.diff
@@ -0,0 +1,25 @@
+diff --git a/nir/src/main/scala/scala/scalanative/nir/serialization/BinarySerializer.scala b/nir/src/main/scala/scala/scalanative/nir/serialization/BinarySerializer.scala
+index eb788a30..f9877297 100644
+--- a/nir/src/main/scala/scala/scalanative/nir/serialization/BinarySerializer.scala
++++ b/nir/src/main/scala/scala/scalanative/nir/serialization/BinarySerializer.scala
+@@ -30,8 +30,9 @@ final class BinarySerializer {
+   import bufferUnderyling.currentPosition
+ 
+   def serialize(defns: Seq[Defn], outputStream: OutputStream): Unit = {
+-    val names     = defns.map(_.name)
+-    val filenames = initFiles(defns)
++    val sortedDefns = defns.sortBy(_.name)
++    val names     = sortedDefns.map(_.name)
++    val filenames = initFiles(sortedDefns)
+     val positions = mutable.UnrolledBuffer.empty[Int]
+ 
+     Prelude.writeTo(buffer,
+@@ -48,7 +49,7 @@ final class BinarySerializer {
+       putInt(0)
+     }
+ 
+-    defns
++    sortedDefns
+       .zip(positions)
+       .foreach {
+         case (defn, marker) =>