diff --git a/ChangeLog.md b/ChangeLog.md
index 32954c9d2a..3abf37bf19 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix analyzer [RCS1182](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1182) ([PR](https://github.com/dotnet/roslynator/pull/1502))
 - Fix analyzer [RCS1198](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1198) ([PR](https://github.com/dotnet/roslynator/pull/1501))
 - Fix analyzer [RCS1214](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1214) ([PR](https://github.com/dotnet/roslynator/pull/1500))
+- Fix analyzer [RCS1018](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1018) ([PR](https://github.com/dotnet/roslynator/pull/1510))
 
 ## [4.12.4] - 2024-06-01
 
diff --git a/src/CSharp/CSharp/SyntaxAccessibility`1.cs b/src/CSharp/CSharp/SyntaxAccessibility`1.cs
index 62824c11bc..c6246657ce 100644
--- a/src/CSharp/CSharp/SyntaxAccessibility`1.cs
+++ b/src/CSharp/CSharp/SyntaxAccessibility`1.cs
@@ -200,6 +200,11 @@ public static Accessibility GetDefaultExplicitAccessibility(BaseTypeDeclarationS
             if (declaration is null)
                 throw new ArgumentNullException(nameof(declaration));
 
+#if ROSLYN_4_4
+            if (declaration.Modifiers.Contains(SyntaxKind.FileKeyword))
+                return Accessibility.NotApplicable;
+#endif
+
 #if ROSLYN_4_0
             return (declaration.IsParentKind(SyntaxKind.ClassDeclaration, SyntaxKind.StructDeclaration, SyntaxKind.RecordDeclaration, SyntaxKind.RecordStructDeclaration))
 #else
@@ -354,6 +359,11 @@ public override Accessibility GetDefaultExplicitAccessibility(DelegateDeclaratio
             if (declaration is null)
                 throw new ArgumentNullException(nameof(declaration));
 
+#if ROSLYN_4_4
+            if (declaration.Modifiers.Contains(SyntaxKind.FileKeyword))
+                return Accessibility.NotApplicable;
+#endif
+
             if (declaration.IsParentKind(
                 SyntaxKind.ClassDeclaration,
                 SyntaxKind.StructDeclaration,
diff --git a/src/Tests/Analyzers.Tests/RCS1018AddAccessibilityModifiersTests.cs b/src/Tests/Analyzers.Tests/RCS1018AddAccessibilityModifiersTests.cs
index e3d97c3460..58e8b43d36 100644
--- a/src/Tests/Analyzers.Tests/RCS1018AddAccessibilityModifiersTests.cs
+++ b/src/Tests/Analyzers.Tests/RCS1018AddAccessibilityModifiersTests.cs
@@ -472,6 +472,22 @@ object I.this[int index]
         }
     }
 }
+", options: Options.AddConfigOption(ConfigOptionKeys.AccessibilityModifiers, ConfigOptionValues.AccessibilityModifiers_Explicit));
+    }
+
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.AddOrRemoveAccessibilityModifiers)]
+    public async Task TestNoDiagnostic_FileAccessModifier()
+    {
+        await VerifyNoDiagnosticAsync(@"
+using System;
+
+file class C;
+file struct S;
+file interface I;
+file record R;
+file record struct RS;
+file delegate void D();
+file enum E;
 ", options: Options.AddConfigOption(ConfigOptionKeys.AccessibilityModifiers, ConfigOptionValues.AccessibilityModifiers_Explicit));
     }
 }