diff --git a/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart b/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
index c058dd69ee2..5a5f80bb7af 100644
--- a/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
@@ -2628,8 +2628,12 @@ class ConstantEvaluator implements ExpressionVisitor<Constant> {
         if (evaluatedResult is AbortConstant) {
           nodeCache.remove(node);
           return evaluatedResult;
-        } else {
+        } else if (lazyDepth == 0) {
           nodeCache[node] = evaluatedResult;
+        } else {
+          // Don't cache nodes evaluated in a lazy region, since these are not
+          // themselves unevaluated but just part of an unevaluated constant.
+          nodeCache.remove(node);
         }
         result = evaluatedResult;
       }
diff --git a/pkg/front_end/testcases/dart2js/conditional_import.dart.strong.expect b/pkg/front_end/testcases/dart2js/conditional_import.dart.strong.expect
index 560176d068f..38b15417afb 100644
--- a/pkg/front_end/testcases/dart2js/conditional_import.dart.strong.expect
+++ b/pkg/front_end/testcases/dart2js/conditional_import.dart.strong.expect
@@ -87,9 +87,9 @@ Try correcting the name to the name of an existing getter, or defining a getter
   request.{core::Object::hashCode}{core::int};
 }
 static method main() → void {
-  self::expect(false, #C1);
-  self::expect(true, #C2);
-  self::expect(false, #C1);
+  self::expect(false, #C2);
+  self::expect(true, #C4);
+  self::expect(false, #C6);
 }
 static method expect(dynamic expected, dynamic actual) → dynamic {
   if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
@@ -97,6 +97,10 @@ static method expect(dynamic expected, dynamic actual) → dynamic {
 }
 
 constants  {
-  #C1 = false
-  #C2 = true
+  #C1 = "dart.library.io"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = "dart.library.html"
+  #C4 = eval const core::bool::fromEnvironment(#C3)
+  #C5 = "dart.library.foo"
+  #C6 = eval const core::bool::fromEnvironment(#C5)
 }
diff --git a/pkg/front_end/testcases/dart2js/conditional_import.dart.strong.transformed.expect b/pkg/front_end/testcases/dart2js/conditional_import.dart.strong.transformed.expect
index 560176d068f..3b4b4733ae9 100644
--- a/pkg/front_end/testcases/dart2js/conditional_import.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/dart2js/conditional_import.dart.strong.transformed.expect
@@ -87,9 +87,9 @@ Try correcting the name to the name of an existing getter, or defining a getter
   request.{core::Object::hashCode}{core::int};
 }
 static method main() → void {
-  self::expect(false, #C1);
-  self::expect(true, #C2);
-  self::expect(false, #C1);
+  self::expect(false, #C2);
+  self::expect(true, #C4);
+  self::expect(false, #C6);
 }
 static method expect(dynamic expected, dynamic actual) → dynamic {
   if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
@@ -97,6 +97,16 @@ static method expect(dynamic expected, dynamic actual) → dynamic {
 }
 
 constants  {
-  #C1 = false
-  #C2 = true
+  #C1 = "dart.library.io"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = "dart.library.html"
+  #C4 = eval const core::bool::fromEnvironment(#C3)
+  #C5 = "dart.library.foo"
+  #C6 = eval const core::bool::fromEnvironment(#C5)
 }
+
+Extra constant evaluation status:
+Evaluated with empty environment: ConstantExpression @ org-dartlang-testcase:///conditional_import.dart:41:23 -> BoolConstant(false)
+Evaluated with empty environment: ConstantExpression @ org-dartlang-testcase:///conditional_import.dart:42:22 -> BoolConstant(true)
+Evaluated with empty environment: ConstantExpression @ org-dartlang-testcase:///conditional_import.dart:43:23 -> BoolConstant(false)
+Extra constant evaluation: evaluated: 29, effectively constant: 3
diff --git a/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.expect b/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.expect
index 560176d068f..38b15417afb 100644
--- a/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.expect
+++ b/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.expect
@@ -87,9 +87,9 @@ Try correcting the name to the name of an existing getter, or defining a getter
   request.{core::Object::hashCode}{core::int};
 }
 static method main() → void {
-  self::expect(false, #C1);
-  self::expect(true, #C2);
-  self::expect(false, #C1);
+  self::expect(false, #C2);
+  self::expect(true, #C4);
+  self::expect(false, #C6);
 }
 static method expect(dynamic expected, dynamic actual) → dynamic {
   if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
@@ -97,6 +97,10 @@ static method expect(dynamic expected, dynamic actual) → dynamic {
 }
 
 constants  {
-  #C1 = false
-  #C2 = true
+  #C1 = "dart.library.io"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = "dart.library.html"
+  #C4 = eval const core::bool::fromEnvironment(#C3)
+  #C5 = "dart.library.foo"
+  #C6 = eval const core::bool::fromEnvironment(#C5)
 }
diff --git a/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.modular.expect b/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.modular.expect
index 560176d068f..38b15417afb 100644
--- a/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.modular.expect
@@ -87,9 +87,9 @@ Try correcting the name to the name of an existing getter, or defining a getter
   request.{core::Object::hashCode}{core::int};
 }
 static method main() → void {
-  self::expect(false, #C1);
-  self::expect(true, #C2);
-  self::expect(false, #C1);
+  self::expect(false, #C2);
+  self::expect(true, #C4);
+  self::expect(false, #C6);
 }
 static method expect(dynamic expected, dynamic actual) → dynamic {
   if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
@@ -97,6 +97,10 @@ static method expect(dynamic expected, dynamic actual) → dynamic {
 }
 
 constants  {
-  #C1 = false
-  #C2 = true
+  #C1 = "dart.library.io"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = "dart.library.html"
+  #C4 = eval const core::bool::fromEnvironment(#C3)
+  #C5 = "dart.library.foo"
+  #C6 = eval const core::bool::fromEnvironment(#C5)
 }
diff --git a/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.transformed.expect b/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.transformed.expect
index 560176d068f..3b4b4733ae9 100644
--- a/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/dart2js/conditional_import.dart.weak.transformed.expect
@@ -87,9 +87,9 @@ Try correcting the name to the name of an existing getter, or defining a getter
   request.{core::Object::hashCode}{core::int};
 }
 static method main() → void {
-  self::expect(false, #C1);
-  self::expect(true, #C2);
-  self::expect(false, #C1);
+  self::expect(false, #C2);
+  self::expect(true, #C4);
+  self::expect(false, #C6);
 }
 static method expect(dynamic expected, dynamic actual) → dynamic {
   if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
@@ -97,6 +97,16 @@ static method expect(dynamic expected, dynamic actual) → dynamic {
 }
 
 constants  {
-  #C1 = false
-  #C2 = true
+  #C1 = "dart.library.io"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = "dart.library.html"
+  #C4 = eval const core::bool::fromEnvironment(#C3)
+  #C5 = "dart.library.foo"
+  #C6 = eval const core::bool::fromEnvironment(#C5)
 }
+
+Extra constant evaluation status:
+Evaluated with empty environment: ConstantExpression @ org-dartlang-testcase:///conditional_import.dart:41:23 -> BoolConstant(false)
+Evaluated with empty environment: ConstantExpression @ org-dartlang-testcase:///conditional_import.dart:42:22 -> BoolConstant(true)
+Evaluated with empty environment: ConstantExpression @ org-dartlang-testcase:///conditional_import.dart:43:23 -> BoolConstant(false)
+Extra constant evaluation: evaluated: 29, effectively constant: 3
diff --git a/pkg/front_end/testcases/dart2js/folder.options b/pkg/front_end/testcases/dart2js/folder.options
index 53ae7285818..f9b0a2dbdee 100644
--- a/pkg/front_end/testcases/dart2js/folder.options
+++ b/pkg/front_end/testcases/dart2js/folder.options
@@ -1 +1,2 @@
---target=dart2js
\ No newline at end of file
+--target=dart2js
+--no-defines
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart b/pkg/front_end/testcases/dart2js/issue51823.dart
new file mode 100644
index 00000000000..f2399edc848
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart
@@ -0,0 +1,7 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'issue51823_lib.dart';
+
+const a = const bool.fromEnvironment('foo') ? E.a : E.b;
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart.strong.expect b/pkg/front_end/testcases/dart2js/issue51823.dart.strong.expect
new file mode 100644
index 00000000000..0c02de0483d
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart.strong.expect
@@ -0,0 +1,59 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "issue51823_lib.dart" as iss;
+
+import "org-dartlang-testcase:///issue51823_lib.dart";
+
+static const field iss::E a = #C9;
+
+library /*isNonNullableByDefault*/;
+import self as iss;
+import "dart:core" as core;
+
+class E extends core::_Enum /*isEnum*/  {
+  static const field core::List<iss::E> values = #C12;
+  enum-element static const field iss::E a = #C10;
+  enum-element static const field iss::E b = #C11;
+  const constructor •(core::int #index, core::String #name) → iss::E
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "E.${this.{core::_Enum::_name}{core::String}}";
+}
+static method method(iss::E e) → dynamic {
+  #L1:
+  switch(e) /*isExplicitlyExhaustive*/ {
+    #L2:
+    case #C10:
+      {
+        return 0;
+      }
+    #L3:
+    case #C11:
+      {
+        return 1;
+      }
+  }
+}
+
+constants  {
+  #C1 = "foo"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = 0.0
+  #C4 = "a"
+  #C5 = eval iss::E{index:#C3, _name:#C4}
+  #C6 = 1.0
+  #C7 = "b"
+  #C8 = eval iss::E{index:#C6, _name:#C7}
+  #C9 = eval #C2 ?{iss::E} #C5 : #C8
+  #C10 = iss::E {index:#C3, _name:#C4}
+  #C11 = iss::E {index:#C6, _name:#C7}
+  #C12 = <iss::E>[#C10, #C11]
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///issue51823_lib.dart:
+- E. (from org-dartlang-testcase:///issue51823_lib.dart:5:6)
+- _Enum. (from org-dartlang-sdk:///lib/core/enum.dart)
+- Object. (from org-dartlang-sdk:///lib/core/object.dart)
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart.strong.transformed.expect b/pkg/front_end/testcases/dart2js/issue51823.dart.strong.transformed.expect
new file mode 100644
index 00000000000..ddcb0b7ad2d
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart.strong.transformed.expect
@@ -0,0 +1,63 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "issue51823_lib.dart" as iss;
+
+import "org-dartlang-testcase:///issue51823_lib.dart";
+
+static const field iss::E a = #C9;
+
+library /*isNonNullableByDefault*/;
+import self as iss;
+import "dart:core" as core;
+
+class E extends core::_Enum /*isEnum*/  {
+  static const field core::List<iss::E> values = #C12;
+  enum-element static const field iss::E a = #C10;
+  enum-element static const field iss::E b = #C11;
+  const constructor •(core::int #index, core::String #name) → iss::E
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "E.${this.{core::_Enum::_name}{core::String}}";
+}
+static method method(iss::E e) → dynamic {
+  #L1:
+  switch(e) /*isExplicitlyExhaustive*/ {
+    #L2:
+    case #C10:
+      {
+        return 0;
+      }
+    #L3:
+    case #C11:
+      {
+        return 1;
+      }
+  }
+}
+
+constants  {
+  #C1 = "foo"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = 0.0
+  #C4 = "a"
+  #C5 = eval iss::E{index:#C3, _name:#C4}
+  #C6 = 1.0
+  #C7 = "b"
+  #C8 = eval iss::E{index:#C6, _name:#C7}
+  #C9 = eval #C2 ?{iss::E} #C5 : #C8
+  #C10 = iss::E {index:#C3, _name:#C4}
+  #C11 = iss::E {index:#C6, _name:#C7}
+  #C12 = <iss::E>[#C10, #C11]
+}
+
+Extra constant evaluation status:
+Evaluated with empty environment: ConstantExpression @ org-dartlang-testcase:///issue51823.dart:7:45 -> InstanceConstant(const E{_Enum.index: 1.0, _Enum._name: "b"})
+Extra constant evaluation: evaluated: 7, effectively constant: 1
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///issue51823_lib.dart:
+- E. (from org-dartlang-testcase:///issue51823_lib.dart:5:6)
+- _Enum. (from org-dartlang-sdk:///lib/core/enum.dart)
+- Object. (from org-dartlang-sdk:///lib/core/object.dart)
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart.textual_outline.expect b/pkg/front_end/testcases/dart2js/issue51823.dart.textual_outline.expect
new file mode 100644
index 00000000000..03f1c310b96
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart.textual_outline.expect
@@ -0,0 +1,3 @@
+import 'issue51823_lib.dart';
+
+const a = const bool.fromEnvironment('foo') ? E.a : E.b;
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart.textual_outline_modelled.expect b/pkg/front_end/testcases/dart2js/issue51823.dart.textual_outline_modelled.expect
new file mode 100644
index 00000000000..03f1c310b96
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart.textual_outline_modelled.expect
@@ -0,0 +1,3 @@
+import 'issue51823_lib.dart';
+
+const a = const bool.fromEnvironment('foo') ? E.a : E.b;
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart.weak.expect b/pkg/front_end/testcases/dart2js/issue51823.dart.weak.expect
new file mode 100644
index 00000000000..64fbd9b5f86
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart.weak.expect
@@ -0,0 +1,63 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "issue51823_lib.dart" as iss;
+
+import "org-dartlang-testcase:///issue51823_lib.dart";
+
+static const field iss::E a = #C9;
+
+library /*isNonNullableByDefault*/;
+import self as iss;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class E extends core::_Enum /*isEnum*/  {
+  static const field core::List<iss::E> values = #C12;
+  enum-element static const field iss::E a = #C10;
+  enum-element static const field iss::E b = #C11;
+  const constructor •(core::int #index, core::String #name) → iss::E
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "E.${this.{core::_Enum::_name}{core::String}}";
+}
+static method method(iss::E e) → dynamic {
+  #L1:
+  switch(e) /*isExplicitlyExhaustive*/ {
+    #L2:
+    case #C10:
+      {
+        return 0;
+      }
+    #L3:
+    case #C11:
+      {
+        return 1;
+      }
+    #L4:
+    default:
+      throw new _in::ReachabilityError::•("`null` encountered as case in a switch statement with a non-nullable type.");
+  }
+}
+
+constants  {
+  #C1 = "foo"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = 0.0
+  #C4 = "a"
+  #C5 = eval iss::E{index:#C3, _name:#C4}
+  #C6 = 1.0
+  #C7 = "b"
+  #C8 = eval iss::E{index:#C6, _name:#C7}
+  #C9 = eval #C2 ?{iss::E} #C5 : #C8
+  #C10 = iss::E {index:#C3, _name:#C4}
+  #C11 = iss::E {index:#C6, _name:#C7}
+  #C12 = <iss::E*>[#C10, #C11]
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///issue51823_lib.dart:
+- E. (from org-dartlang-testcase:///issue51823_lib.dart:5:6)
+- _Enum. (from org-dartlang-sdk:///lib/core/enum.dart)
+- Object. (from org-dartlang-sdk:///lib/core/object.dart)
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart.weak.modular.expect b/pkg/front_end/testcases/dart2js/issue51823.dart.weak.modular.expect
new file mode 100644
index 00000000000..64fbd9b5f86
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart.weak.modular.expect
@@ -0,0 +1,63 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "issue51823_lib.dart" as iss;
+
+import "org-dartlang-testcase:///issue51823_lib.dart";
+
+static const field iss::E a = #C9;
+
+library /*isNonNullableByDefault*/;
+import self as iss;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class E extends core::_Enum /*isEnum*/  {
+  static const field core::List<iss::E> values = #C12;
+  enum-element static const field iss::E a = #C10;
+  enum-element static const field iss::E b = #C11;
+  const constructor •(core::int #index, core::String #name) → iss::E
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "E.${this.{core::_Enum::_name}{core::String}}";
+}
+static method method(iss::E e) → dynamic {
+  #L1:
+  switch(e) /*isExplicitlyExhaustive*/ {
+    #L2:
+    case #C10:
+      {
+        return 0;
+      }
+    #L3:
+    case #C11:
+      {
+        return 1;
+      }
+    #L4:
+    default:
+      throw new _in::ReachabilityError::•("`null` encountered as case in a switch statement with a non-nullable type.");
+  }
+}
+
+constants  {
+  #C1 = "foo"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = 0.0
+  #C4 = "a"
+  #C5 = eval iss::E{index:#C3, _name:#C4}
+  #C6 = 1.0
+  #C7 = "b"
+  #C8 = eval iss::E{index:#C6, _name:#C7}
+  #C9 = eval #C2 ?{iss::E} #C5 : #C8
+  #C10 = iss::E {index:#C3, _name:#C4}
+  #C11 = iss::E {index:#C6, _name:#C7}
+  #C12 = <iss::E*>[#C10, #C11]
+}
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///issue51823_lib.dart:
+- E. (from org-dartlang-testcase:///issue51823_lib.dart:5:6)
+- _Enum. (from org-dartlang-sdk:///lib/core/enum.dart)
+- Object. (from org-dartlang-sdk:///lib/core/object.dart)
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart.weak.outline.expect b/pkg/front_end/testcases/dart2js/issue51823.dart.weak.outline.expect
new file mode 100644
index 00000000000..84863bc0efa
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart.weak.outline.expect
@@ -0,0 +1,36 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "issue51823_lib.dart" as iss;
+import "dart:core" as core;
+
+import "org-dartlang-testcase:///issue51823_lib.dart";
+
+static const field iss::E a = const core::bool::fromEnvironment("foo") ?{iss::E} iss::E::a : iss::E::b;
+
+library /*isNonNullableByDefault*/;
+import self as iss;
+import "dart:core" as core;
+
+class E extends core::_Enum /*isEnum*/  {
+  static const field core::List<iss::E> values = const <iss::E>[iss::E::a, iss::E::b];
+  enum-element static const field iss::E a = const iss::E::•(0, "a");
+  enum-element static const field iss::E b = const iss::E::•(1, "b");
+  const constructor •(core::int #index, core::String #name) → iss::E
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "E.${this.{core::_Enum::_name}{core::String}}";
+}
+static method method(iss::E e) → dynamic
+  ;
+
+
+Extra constant evaluation status:
+Evaluated with empty environment: ConditionalExpression @ org-dartlang-testcase:///issue51823.dart:7:45 -> InstanceConstant(const E{_Enum.index: 1.0, _Enum._name: "b"})
+Evaluated with empty environment: FactoryConstructorInvocation @ org-dartlang-testcase:///issue51823.dart:7:17 -> BoolConstant(false)
+Evaluated: StaticGet @ org-dartlang-testcase:///issue51823.dart:7:49 -> InstanceConstant(const E{_Enum.index: 0.0, _Enum._name: "a"})
+Evaluated: StaticGet @ org-dartlang-testcase:///issue51823.dart:7:55 -> InstanceConstant(const E{_Enum.index: 1.0, _Enum._name: "b"})
+Evaluated: ListLiteral @ org-dartlang-testcase:///issue51823_lib.dart:5:6 -> ListConstant(const <E*>[const E{_Enum.index: 0.0, _Enum._name: "a"}, const E{_Enum.index: 1.0, _Enum._name: "b"}])
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///issue51823_lib.dart:5:10 -> InstanceConstant(const E{_Enum.index: 0.0, _Enum._name: "a"})
+Evaluated: ConstructorInvocation @ org-dartlang-testcase:///issue51823_lib.dart:5:13 -> InstanceConstant(const E{_Enum.index: 1.0, _Enum._name: "b"})
+Extra constant evaluation: evaluated: 12, effectively constant: 7
diff --git a/pkg/front_end/testcases/dart2js/issue51823.dart.weak.transformed.expect b/pkg/front_end/testcases/dart2js/issue51823.dart.weak.transformed.expect
new file mode 100644
index 00000000000..40638455e44
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823.dart.weak.transformed.expect
@@ -0,0 +1,67 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "issue51823_lib.dart" as iss;
+
+import "org-dartlang-testcase:///issue51823_lib.dart";
+
+static const field iss::E a = #C9;
+
+library /*isNonNullableByDefault*/;
+import self as iss;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class E extends core::_Enum /*isEnum*/  {
+  static const field core::List<iss::E> values = #C12;
+  enum-element static const field iss::E a = #C10;
+  enum-element static const field iss::E b = #C11;
+  const constructor •(core::int #index, core::String #name) → iss::E
+    : super core::_Enum::•(#index, #name)
+    ;
+  method _enumToString() → core::String
+    return "E.${this.{core::_Enum::_name}{core::String}}";
+}
+static method method(iss::E e) → dynamic {
+  #L1:
+  switch(e) /*isExplicitlyExhaustive*/ {
+    #L2:
+    case #C10:
+      {
+        return 0;
+      }
+    #L3:
+    case #C11:
+      {
+        return 1;
+      }
+    #L4:
+    default:
+      throw new _in::ReachabilityError::•("`null` encountered as case in a switch statement with a non-nullable type.");
+  }
+}
+
+constants  {
+  #C1 = "foo"
+  #C2 = eval const core::bool::fromEnvironment(#C1)
+  #C3 = 0.0
+  #C4 = "a"
+  #C5 = eval iss::E{index:#C3, _name:#C4}
+  #C6 = 1.0
+  #C7 = "b"
+  #C8 = eval iss::E{index:#C6, _name:#C7}
+  #C9 = eval #C2 ?{iss::E} #C5 : #C8
+  #C10 = iss::E {index:#C3, _name:#C4}
+  #C11 = iss::E {index:#C6, _name:#C7}
+  #C12 = <iss::E*>[#C10, #C11]
+}
+
+Extra constant evaluation status:
+Evaluated with empty environment: ConstantExpression @ org-dartlang-testcase:///issue51823.dart:7:45 -> InstanceConstant(const E{_Enum.index: 1.0, _Enum._name: "b"})
+Extra constant evaluation: evaluated: 9, effectively constant: 1
+
+
+Constructor coverage from constants:
+org-dartlang-testcase:///issue51823_lib.dart:
+- E. (from org-dartlang-testcase:///issue51823_lib.dart:5:6)
+- _Enum. (from org-dartlang-sdk:///lib/core/enum.dart)
+- Object. (from org-dartlang-sdk:///lib/core/object.dart)
diff --git a/pkg/front_end/testcases/dart2js/issue51823_lib.dart b/pkg/front_end/testcases/dart2js/issue51823_lib.dart
new file mode 100644
index 00000000000..af480a3c95f
--- /dev/null
+++ b/pkg/front_end/testcases/dart2js/issue51823_lib.dart
@@ -0,0 +1,14 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+enum E { a, b }
+
+method(E e) {
+  switch (e) {
+    case E.a:
+      return 0;
+    case E.b:
+      return 1;
+  }
+}
diff --git a/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various_2.dart.weak.outline.expect b/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various_2.dart.weak.outline.expect
index b50503813cf..75ed24cd364 100644
--- a/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various_2.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various_2.dart.weak.outline.expect
@@ -113,10 +113,8 @@ Evaluated: TypeLiteral @ org-dartlang-testcase:///various_2_lib.dart:17:27 -> Ty
 Evaluated: StaticTearOff @ org-dartlang-testcase:///various_2_lib.dart:18:12 -> StaticTearOffConstant(identical)
 Evaluated with empty environment: ConditionalExpression @ org-dartlang-testcase:///various_2_lib.dart:20:39 -> InstantiationConstant(id2<int*>)
 Evaluated with empty environment: FactoryConstructorInvocation @ org-dartlang-testcase:///various_2_lib.dart:20:11 -> BoolConstant(false)
-Evaluated with empty environment: Instantiation @ org-dartlang-testcase:///various_2_lib.dart:20:41 -> InstantiationConstant(id1<int*>)
-Evaluated: StaticTearOff @ org-dartlang-testcase:///various_2_lib.dart:20:41 -> StaticTearOffConstant(id1)
-Evaluated with empty environment: Instantiation @ org-dartlang-testcase:///various_2_lib.dart:20:47 -> InstantiationConstant(id2<int*>)
-Evaluated: StaticTearOff @ org-dartlang-testcase:///various_2_lib.dart:20:47 -> StaticTearOffConstant(id2)
+Evaluated: Instantiation @ org-dartlang-testcase:///various_2_lib.dart:20:41 -> InstantiationConstant(id1<int*>)
+Evaluated: Instantiation @ org-dartlang-testcase:///various_2_lib.dart:20:47 -> InstantiationConstant(id2<int*>)
 Evaluated: ConstructorInvocation @ org-dartlang-testcase:///various_2_lib.dart:21:24 -> InstanceConstant(const Class<int*>{Class.field: 0})
 Evaluated: ConstructorInvocation @ org-dartlang-testcase:///various_2_lib.dart:22:25 -> InstanceConstant(const Class<dynamic>{Class.field: const <int*>[42]})
 Evaluated: TypeLiteral @ org-dartlang-testcase:///various_2_lib.dart:23:29 -> TypeLiteralConstant(dynamic Function(dynamic)*)
@@ -130,4 +128,4 @@ Evaluated: MapLiteral @ org-dartlang-testcase:///various_2_lib.dart:34:39 -> Map
 Evaluated: ListConcatenation @ org-dartlang-testcase:///various_2_lib.dart:38:32 -> ListConstant(const <int*>[0])
 Evaluated: SetConcatenation @ org-dartlang-testcase:///various_2_lib.dart:39:31 -> SetConstant(const <int*>{0})
 Evaluated: MapConcatenation @ org-dartlang-testcase:///various_2_lib.dart:40:7 -> MapConstant(const <int*, String*>{0: "foo"})
-Extra constant evaluation: evaluated: 54, effectively constant: 53
+Extra constant evaluation: evaluated: 52, effectively constant: 51