diff --git a/artiq-fast/conda-windows/binutils-recipe/bld.bat b/artiq-fast/conda-windows/binutils-recipe/bld.bat
index fa5fe84..90e4ff0 100644
--- a/artiq-fast/conda-windows/binutils-recipe/bld.bat
+++ b/artiq-fast/conda-windows/binutils-recipe/bld.bat
@@ -1,21 +1,7 @@
 set MSYS=C:\MSYS64
-set TRIPLE=x86_64-pc-mingw64
 set PATH=%MSYS%\usr\bin;%MSYS%\mingw64\bin;%PATH%
 
-mkdir build
-cd build
-set CFLAGS=-I%PREFIX:\=/%/Library/include/
-set LDFLAGS=-L%PREFIX:\=/%/Library/lib/
-sh ../configure --build=%TRIPLE% ^
-  --prefix="%PREFIX:\=/%/Library" ^
-  --target=##TARGET##
-if errorlevel 1 exit 1
-
-make -j4
-if errorlevel 1 exit 1
-
-make install
-if errorlevel 1 exit 1
-
-rem this is a copy of prefixed executables
-rmdir /S /Q %PREFIX%\Library\##TARGET##
+cd %PREFIX%
+tar xjf /c/Users/wfvm/src.tar.bz2
+dir C:\Users\wfvm
+python C:\Users\wfvm\patch_prefix.py "##PREFIX##" %PREFIX%
diff --git a/artiq-fast/conda-windows/binutils.nix b/artiq-fast/conda-windows/binutils.nix
index 6358ebe..b58f9a4 100644
--- a/artiq-fast/conda-windows/binutils.nix
+++ b/artiq-fast/conda-windows/binutils.nix
@@ -1,4 +1,4 @@
-{ pkgs, version, src, target }:
+{ pkgs, version, target, windows-binutils }:
 
 let
   wfvm = import ../wfvm.nix { inherit pkgs; };
@@ -34,11 +34,13 @@ let
       cp --no-preserve=mode,ownership -R ${./binutils-recipe} binutils
       sed -i s/##TARGET##/${target}/g binutils/*
       sed -i s/##VERSION##/${version}/g binutils/*
+      sed -i 's!##PREFIX##!${windows-binutils.prefix}!g' binutils/*
       ${wfvm.utils.win-put}/bin/win-put binutils .
-      tar xjf ${src}
-      patch -d binutils-${version} -p1 < ${./binutils-hack-libiconv.patch}
-      tar cjf src.tar.bz2 binutils-${version}
+      cp ${windows-binutils} src.tar.bz2
       ${wfvm.utils.win-put}/bin/win-put src.tar.bz2 .
+      cp ${./patch_prefix.py} patch_prefix.py
+      ls -l patch_prefix.py
+      ${wfvm.utils.win-put}/bin/win-put patch_prefix.py .
 
       ${wfvm.utils.win-exec}/bin/win-exec ".\Anaconda3\scripts\activate && conda build --no-anaconda-upload --no-test -c file:///C:/users/wfvm/fake-channel --override-channels binutils"
 
diff --git a/artiq-fast/conda-windows/patch_prefix.py b/artiq-fast/conda-windows/patch_prefix.py
new file mode 100644
index 0000000..083d15c
--- /dev/null
+++ b/artiq-fast/conda-windows/patch_prefix.py
@@ -0,0 +1,35 @@
+import os, sys, re
+
+OLD = sys.argv[1].encode('utf-8')
+NEW = sys.argv[2].encode('utf-8')
+
+if len(NEW) > len(OLD):
+    raise ValueError("Cannot new shorter than the replacement")
+new = NEW + b"\0" * (len(OLD) - len(NEW))
+
+def patch_file(path):
+    with open(path, "r+b") as f:
+        s = f.read()
+    occurrences = s.count(OLD)
+    s = s.replace(OLD, new)
+    if occurrences > 0:
+        print("{}: replaced {}, left {}".format(path, occurrences, s.count(OLD)))
+    with open(path, "w+b") as f:
+        f.write(s)
+
+for root, dirs, files in os.walk("."):
+    for filename in files:
+        path = "{}/{}".format(root, filename)
+        patch_file(path)
+
+def mangle_path(path):
+    path = re.sub(r"^/c/", "C:/", path)
+    return str(path)
+        
+OLD = mangle_path(sys.argv[1]).encode('utf-8')
+NEW = mangle_path(sys.argv[2]).encode('utf-8')
+        
+for root, dirs, files in os.walk("."):
+    for filename in files:
+        path = "{}/{}".format(root, filename)
+        patch_file(path)
diff --git a/artiq-fast/default.nix b/artiq-fast/default.nix
index 0569314..d0705ae 100644
--- a/artiq-fast/default.nix
+++ b/artiq-fast/default.nix
@@ -124,11 +124,17 @@ let
   };
 
   condaWindowsExperimental = rec {
-    conda-windows-binutils-or1k = import ./conda-windows/binutils.nix {
+    windows-binutils-or1k = import ./windows/binutils.nix {
       inherit pkgs;
       inherit (mainPackages.binutils-or1k) version src;
       target = "or1k-linux";
     };
+    conda-windows-binutils-or1k = import ./conda-windows/binutils.nix {
+      inherit pkgs;
+      inherit (mainPackages.binutils-or1k) version;
+      target = "or1k-linux";
+      windows-binutils = windows-binutils-or1k;
+    };
     conda-windows-binutils-arm = import ./conda-windows/binutils.nix {
       inherit pkgs;
       inherit (mainPackages.binutils-or1k) version src;
diff --git a/artiq-fast/conda-windows/binutils-hack-libiconv.patch b/artiq-fast/windows/binutils-hack-libiconv.patch
similarity index 100%
rename from artiq-fast/conda-windows/binutils-hack-libiconv.patch
rename to artiq-fast/windows/binutils-hack-libiconv.patch
diff --git a/artiq-fast/windows/binutils.nix b/artiq-fast/windows/binutils.nix
new file mode 100644
index 0000000..0330b81
--- /dev/null
+++ b/artiq-fast/windows/binutils.nix
@@ -0,0 +1,45 @@
+{ pkgs, version, src, target }:
+
+let
+  wfvm = import ../wfvm.nix { inherit pkgs; };
+  repeat = s:
+    let go = n:
+          if n > 0
+          then s + go (n - 1)
+          else "";
+    in go;
+  outName = "windows-binutils-${target}-${version}.tar.bz2";
+  # add padding for later PREFIX replacement in `conda build`
+  prefix = "/c/Users/wfvm/binutils_" + repeat "0" 80;
+  build = wfvm.utils.wfvm-run {
+    name = "build-binutils";
+    image = wfvm.makeWindowsImage { installCommands = with wfvm.layers; [ msys2 (msys2-packages (import ../conda-windows/msys_packages.nix { inherit pkgs; } )) ]; };
+    script = ''
+      tar xjf ${src}
+      patch -d binutils-${version} -p1 < ${./binutils-hack-libiconv.patch}
+      tar cjf src.tar.bz2 binutils-${version}
+      ${wfvm.utils.win-put}/bin/win-put src.tar.bz2 .
+
+      cat > build-binutils.bat << EOF
+      set MSYS=c:\msys64
+      set PATH=%MSYS%\usr\bin;%MSYS%\mingw64\bin;%PATH%
+      tar xjf src.tar.bz2
+      bash -c "cd binutils-${version} && ./configure --build=x86_64-pc-mingw64 --prefix=${prefix}/Library --target=${target} && make -j$NIX_BUILD_CORES && make install"
+      rm -r ${prefix}/Library/or1k-linux
+      cp %MSYS%/mingw64/bin/libiconv-2.dll ${prefix}/Library/bin/
+      tar cjf ${outName} -C ${prefix} .
+      EOF
+      ${wfvm.utils.win-put}/bin/win-put build-binutils.bat .
+      ${wfvm.utils.win-exec}/bin/win-exec build-binutils
+
+      ${wfvm.utils.win-get}/bin/win-get ${outName}
+    '';
+  };
+in
+pkgs.runCommand outName {
+  buildInputs = [ build ];
+  passthru = { inherit prefix; };
+} ''
+    wfvm-run-build-binutils
+    cp ${outName} $out
+  ''