diff --git a/build.py b/build.py
index 8c6a89e4..04d42d6c 100755
--- a/build.py
+++ b/build.py
@@ -210,11 +210,21 @@ def store_system_config_in_globals(config):
 # The actual build steps.
 #
 
-def checkout_correct_unreal_engine_branch():
+def checkout_correct_unreal_engine_branch_and_apply_patch():
     """
-    This is the version of Unreal Engine that we're currently using.
+    Check out the correct branch, then apply a patch to the UnrealEngine 
+    source code.  Patch application consists of two steps: first, checkout clean,
+    unpatched versions of the files from git.  Then, apply the patch to the clean code.
+    Note: don't git-commit the patch in UnrealEngine.  Instead,
+    just let this script reapply this patch as necessary.
     """
-    shell(UNREALENGINE, "git checkout 5.3.1-release")
+    patch = Path(f"{INTEGRATION}/EnginePatches/EnginePatch")
+    patch_lines = patch.read_text().splitlines()
+    patched_files = [line[6:] for line in patch_lines if line.startswith("--- a/")]
+    for file in patched_files:
+        shell(UNREALENGINE, f"git show HEAD:{file} > {file}")
+    shell(UNREALENGINE, f"git checkout 5.3.1-release")
+    shell(UNREALENGINE, f"git apply {INTEGRATION}/EnginePatches/EnginePatch")
 
 
 def generate_buildconfiguration_xml():
@@ -251,24 +261,6 @@ def generate_lpx_paths():
     target.write_text(code)
 
 
-def patch_unrealengine_source_code():
-    """
-    Apply a patch to the UnrealEngine source code.
-    I tried to avoid patching Unreal engine, but it turns out there are a
-    few things that I just couldn't avoid having to fix.
-    Patch application consists of two steps: first, checkout clean, unpatched
-    versions of the files from git.  Then, apply the patch to the clean code.
-    Note: don't git-commit the patch in UnrealEngine.  Instead,
-    just let this script reapply this patch as necessary.
-    """
-    patch = Path(f"{INTEGRATION}/EnginePatches/EnginePatch")
-    patch_lines = patch.read_text().splitlines()
-    patched_files = [line[6:] for line in patch_lines if line.startswith("--- a/")]
-    for file in patched_files:
-        shell(UNREALENGINE, f"git show HEAD:{file} > {file}")
-    shell(UNREALENGINE, f"git apply {INTEGRATION}/EnginePatches/EnginePatch")
-
-
 def generate_integration_uproject():
     """
     Generate integration.uproject
@@ -379,10 +371,9 @@ store_system_config_in_globals(CONFIG)
 os.chdir(f"{INTEGRATION}/EnginePatches")
 
 if MODE == "all":
-    checkout_correct_unreal_engine_branch()
+    checkout_correct_unreal_engine_branch_and_apply_patch()
     generate_buildconfiguration_xml()
     generate_lpx_paths()
-    patch_unrealengine_source_code()
     generate_integration_uproject()
     run_unrealengine_setup_bat()
     build_unrealbuildtool()