diff --git a/analysis_options.yaml b/analysis_options.yaml
index 27ed3cd..e42fee8 100644
--- a/analysis_options.yaml
+++ b/analysis_options.yaml
@@ -36,7 +36,7 @@
   - list_remove_unrelated_type
   - no_adjacent_strings_in_list
   - no_duplicate_case_values
-  # non_constant_identifier_names
+  - non_constant_identifier_names
   - null_closures
   - omit_local_variable_types
   - only_throw_errors
diff --git a/lib/src/utils.dart b/lib/src/utils.dart
index c29ad64..dcdecbd 100644
--- a/lib/src/utils.dart
+++ b/lib/src/utils.dart
@@ -55,11 +55,11 @@
 
 /// A regular expression that matches strings that are composed entirely of
 /// ASCII-compatible characters.
-final RegExp _ASCII_ONLY = RegExp(r'^[\x00-\x7F]+$');
+final _asciiOnly = RegExp(r'^[\x00-\x7F]+$');
 
 /// Returns whether [string] is composed entirely of ASCII-compatible
 /// characters.
-bool isPlainAscii(String string) => _ASCII_ONLY.hasMatch(string);
+bool isPlainAscii(String string) => _asciiOnly.hasMatch(string);
 
 /// Converts [input] into a [Uint8List].
 ///