diff --git a/pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart b/pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart
index a8705b11ac5..53435d95804 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart
@@ -7670,12 +7670,11 @@ class InferenceVisitorImpl extends InferenceVisitorBase
     // Note that a switch statement with a `default` clause is always considered
     // exhaustive, but the kernel format also keeps track of whether the switch
     // statement is "explicitly exhaustive", meaning that it has a `case` clause
-    // for every possible enum value.  So if there's a `default` clause we need
-    // to call `isSwitchExhaustive` to figure out whether the switch is
-    // *explicitly* exhaustive.
-    node.isExplicitlyExhaustive = analysisResult.hasDefault
-        ? isLegacySwitchExhaustive(node, analysisResult.scrutineeType)
-        : analysisResult.isExhaustive;
+    // for every possible enum value.  It is only necessary to set this flag if
+    // the switch doesn't have a `default` clause.
+    if (!analysisResult.hasDefault) {
+      node.isExplicitlyExhaustive = analysisResult.isExhaustive;
+    }
     _enumFields = previousEnumFields;
     // Stack: (Expression)
     Node? rewrite = popRewrite();
@@ -8764,7 +8763,9 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   @override
   void handleSwitchScrutinee(DartType type) {
-    if (type is InterfaceType && type.classNode.isEnum) {
+    if (!options.patternsEnabled &&
+        type is InterfaceType &&
+        type.classNode.isEnum) {
       _enumFields = <Field?>{
         ...type.classNode.fields.where((Field field) => field.isEnumElement),
         if (type.isPotentiallyNullable) null
diff --git a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.strong.expect b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.strong.expect
index 0629e562fa2..fa58db588b8 100644
--- a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.strong.expect
@@ -63,7 +63,7 @@ static method method3(self::Enum? e) → core::int {
   }
 }
 static method method4(self::Enum? e) → core::int {
-  switch(e) /*isExplicitlyExhaustive*/ {
+  switch(e) {
     #L6:
     case #C3:
     case #C6:
diff --git a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.strong.transformed.expect
index 0629e562fa2..fa58db588b8 100644
--- a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.strong.transformed.expect
@@ -63,7 +63,7 @@ static method method3(self::Enum? e) → core::int {
   }
 }
 static method method4(self::Enum? e) → core::int {
-  switch(e) /*isExplicitlyExhaustive*/ {
+  switch(e) {
     #L6:
     case #C3:
     case #C6:
diff --git a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.expect b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.expect
index 8e6c5c22993..7966201fc8e 100644
--- a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.expect
@@ -67,7 +67,7 @@ static method method3(self::Enum? e) → core::int {
   }
 }
 static method method4(self::Enum? e) → core::int {
-  switch(e) /*isExplicitlyExhaustive*/ {
+  switch(e) {
     #L7:
     case #C3:
     case #C6:
diff --git a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.modular.expect b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.modular.expect
index 8e6c5c22993..7966201fc8e 100644
--- a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.modular.expect
@@ -67,7 +67,7 @@ static method method3(self::Enum? e) → core::int {
   }
 }
 static method method4(self::Enum? e) → core::int {
-  switch(e) /*isExplicitlyExhaustive*/ {
+  switch(e) {
     #L7:
     case #C3:
     case #C6:
diff --git a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.transformed.expect
index 8e6c5c22993..7966201fc8e 100644
--- a/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/switch_nullable_enum.dart.weak.transformed.expect
@@ -67,7 +67,7 @@ static method method3(self::Enum? e) → core::int {
   }
 }
 static method method4(self::Enum? e) → core::int {
-  switch(e) /*isExplicitlyExhaustive*/ {
+  switch(e) {
     #L7:
     case #C3:
     case #C6:
diff --git a/pkg/kernel/lib/ast.dart b/pkg/kernel/lib/ast.dart
index e2b2ea79617..ea6aaf510ef 100644
--- a/pkg/kernel/lib/ast.dart
+++ b/pkg/kernel/lib/ast.dart
@@ -10394,7 +10394,9 @@ class SwitchStatement extends Statement {
   Expression expression;
   final List<SwitchCase> cases;
 
-  /// For enum switches, whether all enum values are covered by a switch case.
+  /// For switches without a default clause, whether all possible values are
+  /// covered by a switch case.  For switches with a default clause, always
+  /// `false`.
   /// Initialized during type inference.
   bool isExplicitlyExhaustive;