diff --git a/pkg/front_end/lib/src/api_prototype/compiler_options.dart b/pkg/front_end/lib/src/api_prototype/compiler_options.dart
index 0864dae0f7c..0040b7502bf 100644
--- a/pkg/front_end/lib/src/api_prototype/compiler_options.dart
+++ b/pkg/front_end/lib/src/api_prototype/compiler_options.dart
@@ -99,10 +99,6 @@ class CompilerOptions {
   /// List of names that are allowed in dynamic calls in dynamic modules.
   List<String> dynamicCallsSelectorAllowList = [];
 
-  /// The declared variables for use by configurable imports and constant
-  /// evaluation.
-  Map<String, String>? declaredVariables;
-
   /// The [FileSystem] which should be used by the front end to access files.
   ///
   /// All file system access performed by the front end goes through this
@@ -285,7 +281,6 @@ class CompilerOptions {
         other.dynamicInterfaceSpecificationUri) {
       return false;
     }
-    if (!equalMaps(declaredVariables, other.declaredVariables)) return false;
     if (fileSystem != other.fileSystem) return false;
     if (compileSdk != other.compileSdk) return false;
     // chaseDependencies aren't used anywhere, so ignored here.