diff --git a/EnginePatches/PatchedDosFiles b/EnginePatches/PatchedDosFiles
new file mode 100644
index 00000000..640c7639
--- /dev/null
+++ b/EnginePatches/PatchedDosFiles
@@ -0,0 +1 @@
+Setup.bat
diff --git a/build.py b/build.py
index d4aabf7e..f256c5a0 100755
--- a/build.py
+++ b/build.py
@@ -96,26 +96,19 @@ def expand_json_file(sourcefile, outputfile, config):
 # patch, and then convert the appropriate files back.
 #
 
-def patched_files(patchfn):
-    patch_lines = Path(patchfn).read_text().splitlines()
-    file_names = [line[4:].split()[0] for line in patch_lines if line.startswith('--- ')]
-    return [ '/'.join(file.split('/')[1:]) for file in file_names ]
-
 def dos2unix(fn):
-    before = Path(fn).read_text()
-    after = before.replace("\r\n", "\n")
+    before = Path(fn).read_bytes()
+    after = before.replace(b"\r\n", b"\n")
     if before != after:
-        Path(fn).write_text(after)
-        return True
-    return False
+        print("dos2unix ", fn)
+        Path(fn).write_bytes(after)
 
 def unix2dos(fn):
-    before = Path(fn).read_text()
-    after = before.replace("\n", "\r\n")
+    before = Path(fn).read_bytes()
+    after = before.replace(b"\n", b"\r\n")
     if before != after:
-        Path(fn).write_text(after)
-        return True
-    return False
+        print("unix2dos ", fn)
+        Path(fn).write_bytes(after)
 
 #
 # Given a patch file, generate a list of the files being modified.
@@ -203,12 +196,11 @@ def unzip_unreal_engine_and_apply_patch():
         shutil.rmtree(unrealversion, ignore_errors=True)
         shell(INTEGRATION, "unzip UnrealEngine.zip")
         patchfile = f"{INTEGRATION}/EnginePatches/EnginePatch"
+        dosfiles = Path(f"{INTEGRATION}/EnginePatches/PatchedDosFiles").read_text().splitlines()
         dos2unix(patchfile)
-        rel_files = patched_files(patchfile)
-        abs_files = [ os.path.join(unrealversion, file) for file in rel_files ]
-        dos_files = [ file for file in abs_files if dos2unix(file)]
+        for file in dosfiles: dos2unix(f"{unrealversion}/{file}")
         shell(unrealversion, f"patch -p1 < {patchfile}")
-        for file in dos_files: unix2dos(file)
+        for file in dosfiles: unix2dos(f"{unrealversion}/{file}")
         Path(unrealversion).rename(UNREALENGINE)
 
 def generate_buildconfiguration_xml():