diff --git a/pylint/checkers/logging.py b/pylint/checkers/logging.py
index a1fc1099c0..b3a6845b2f 100644
--- a/pylint/checkers/logging.py
+++ b/pylint/checkers/logging.py
@@ -105,12 +105,7 @@
     "warning",
 }
 
-MOST_COMMON_FORMATTING = {
-    "%s",
-    "%d",
-    "%f",
-    "%r",
-}
+MOST_COMMON_FORMATTING = frozenset("%s", "%d", "%f", "%r")
 
 
 def is_method_call(