diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9e18652..3174690 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -16,7 +16,7 @@ repos:
     - id: check-toml
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: 'v0.9.9'
+    rev: 'v0.11.4'
     hooks:
     - id: ruff
       args: [--fix, --exit-non-zero-on-fix]
diff --git a/cycquery/post_process/mimiciv.py b/cycquery/post_process/mimiciv.py
index b0f7d8c..fc1bb04 100644
--- a/cycquery/post_process/mimiciv.py
+++ b/cycquery/post_process/mimiciv.py
@@ -147,7 +147,7 @@ def process_mimic_care_units(
     for unit, unit_dict in CARE_UNIT_MAP.items():
         for specific_unit, unit_list in unit_dict.items():
             value = specific_unit if specific else unit
-            replace_dict.update({elem: value for elem in unit_list})
+            replace_dict.update(dict.fromkeys(unit_list, value))
     transfers[CARE_UNIT].replace(replace_dict, inplace=True)
 
     transfers.dropna(inplace=True)