diff --git a/infra/config/recipes.cfg b/infra/config/recipes.cfg
index cd9afd2..cee3491 100644
--- a/infra/config/recipes.cfg
+++ b/infra/config/recipes.cfg
@@ -18,7 +18,7 @@
   "deps": {
     "recipe_engine": {
       "branch": "refs/heads/main",
-      "revision": "eb434718b27659fb36792b710cf2b80b8d85aa0b",
+      "revision": "c406446548974dc887dac0a676838e08e09b526a",
       "url": "https://chromium.googlesource.com/infra/luci/recipes-py"
     }
   },
diff --git a/recipes.py b/recipes.py
index 05ca941..c6ef83a 100755
--- a/recipes.py
+++ b/recipes.py
@@ -235,13 +235,10 @@
   if not shutil.which(vpython):
     return f'Required binary is not found on PATH: {vpython}'
 
-  # We unset PYTHONPATH here in case the user has conflicting environmental
-  # things we don't want them to leak through into the recipe_engine which
-  # manages its environment entirely via vpython.
-  #
-  # NOTE: os.unsetenv unhelpfully doesn't exist on all platforms until python3.9
-  # so we have to use the cutesy `pop` formulation below until then...
-  os.environ.pop("PYTHONPATH", None)
+  # We overwrite PYTHONPATH here on purpose; We don't want any conflicting
+  # environmental path leaking through into the recipe_engine which manages its
+  # environment entirely via vpython.
+  os.environ['PYTHONPATH'] = engine_path
 
   spec = '.vpython3'
   debugger = os.environ.get('RECIPE_DEBUGGER', '')