diff --git a/Directory.Packages.props b/Directory.Packages.props
index 1078ab14ea..174afd89a4 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -4,8 +4,8 @@
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="Acornima" Version="1.2.0" />
-    <PackageVersion Include="Acornima.Extras" Version="1.2.0" />
+    <PackageVersion Include="Acornima" Version="1.3.0" />
+    <PackageVersion Include="Acornima.Extras" Version="1.3.0" />
     <PackageVersion Include="BenchmarkDotNet" Version="0.15.8" />
     <PackageVersion Include="BenchmarkDotNet.TestAdapter" Version="0.13.12" />
     <PackageVersion Include="FluentAssertions" Version="[7.2.1]" />
@@ -35,4 +35,4 @@
   <ItemGroup>
     <GlobalPackageReference Include="PolySharp" Version="1.15.0" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/Jint.Tests.Test262/Test262Harness.settings.json b/Jint.Tests.Test262/Test262Harness.settings.json
index 470e449bea..83e3cf5902 100644
--- a/Jint.Tests.Test262/Test262Harness.settings.json
+++ b/Jint.Tests.Test262/Test262Harness.settings.json
@@ -6,7 +6,6 @@
   "Parallel": true,
   "ExcludedFeatures": [
     "import-defer",
-    "regexp-modifiers",
     "regexp-unicode-property-escapes",
     "regexp-v-flag",
     "source-phase-imports",
@@ -52,6 +51,14 @@
     "built-ins/RegExp/nullable-quantifier.js",
     "built-ins/RegExp/lookahead-quantifier-match-groups.js",
 
+    // .NET regex engine: scoped regexp modifiers don't fully match ECMAScript boundary and multiline semantics
+    "built-ins/RegExp/regexp-modifiers/add-ignoreCase-affects-slash-lower-b.js",
+    "built-ins/RegExp/regexp-modifiers/add-ignoreCase-affects-slash-lower-w.js",
+    "built-ins/RegExp/regexp-modifiers/add-ignoreCase-affects-slash-upper-b.js",
+    "built-ins/RegExp/regexp-modifiers/add-ignoreCase-affects-slash-upper-w.js",
+    "built-ins/RegExp/regexp-modifiers/add-multiline.js",
+    "built-ins/RegExp/regexp-modifiers/remove-multiline-does-not-affect-dotAll-flag.js",
+
     // .NET regex engine: complex quantifier capture group tracking differs
     "built-ins/RegExp/S15.10.2.5_A1_T4.js",
     "built-ins/RegExp/prototype/exec/S15.10.6.2_A1_T6.js",
@@ -288,4 +295,4 @@
     // Per B.1.2, non-unicode RegExp should accept some malformed named group syntax
     "annexB/built-ins/RegExp/named-groups/non-unicode-malformed.js"
   ]
-}
\ No newline at end of file
+}
diff --git a/Jint.Tests/Runtime/RegExpTests.cs b/Jint.Tests/Runtime/RegExpTests.cs
index 6508123533..d286e90f1e 100644
--- a/Jint.Tests/Runtime/RegExpTests.cs
+++ b/Jint.Tests/Runtime/RegExpTests.cs
@@ -132,6 +132,23 @@ public void ShouldAllowProblematicGroupNames()
         Assert.Equal("a-b-c", result);
     }
 
+    [Fact]
+    public void ShouldSupportRegExpModifiersInLiteralsAndConstructor()
+    {
+        var engine = new Engine();
+
+        var prepared = Engine.PrepareScript("""
+            const literal = /(?m-i:^a$)/i;
+            `${literal.test('A\n')},${literal.test('a\n')}`;
+            """);
+
+        engine.Evaluate(prepared).AsString().Should().Be("false,true");
+        engine.Evaluate("""
+            const regex = new RegExp("(?m-i:^a$)", "i");
+            `${regex.test('A\n')},${regex.test('a\n')}`;
+            """).AsString().Should().Be("false,true");
+    }
+
     [Fact]
     public void Issue506()
     {
diff --git a/Jint/Engine.Defaults.cs b/Jint/Engine.Defaults.cs
index 95a942dfbe..1517bde464 100644
--- a/Jint/Engine.Defaults.cs
+++ b/Jint/Engine.Defaults.cs
@@ -9,6 +9,7 @@ public partial class Engine
         EcmaVersion = EcmaVersion.ES2023,
         ExperimentalESFeatures = ExperimentalESFeatures.ImportAttributes
                                  | ExperimentalESFeatures.RegExpDuplicateNamedCapturingGroups
+                                 | ExperimentalESFeatures.RegExpModifiers
                                  | ExperimentalESFeatures.ExplicitResourceManagement
                                  | ExperimentalESFeatures.Decorators,
         Tolerant = false,