diff --git a/Sources/Rules/RedundantPublic.swift b/Sources/Rules/RedundantPublic.swift
index 4dd47a5d..6ff73014 100644
--- a/Sources/Rules/RedundantPublic.swift
+++ b/Sources/Rules/RedundantPublic.swift
@@ -59,7 +59,8 @@ public extension FormatRule {
                 // Inside an extension where the extended type is internal, any `public` modifier has no effect.
                 // We can only handle this case if the extension and type are defined in the same file.
                 if let extendedTypeName = parentType.name,
-                   internalTypes.contains(extendedTypeName)
+                   internalTypes.contains(extendedTypeName) ||
+                   internalTypes.contains(where: { extendedTypeName.hasPrefix($0 + ".") })
                 {
                     declaration.removeVisibility(.public)
                 }
diff --git a/Tests/Rules/RedundantPublicTests.swift b/Tests/Rules/RedundantPublicTests.swift
index 48fa0caa..b4c783a0 100644
--- a/Tests/Rules/RedundantPublicTests.swift
+++ b/Tests/Rules/RedundantPublicTests.swift
@@ -195,6 +195,29 @@ final class RedundantPublicTests: XCTestCase {
         testFormatting(for: input, [output], rules: [.redundantPublic])
     }
 
+    func testRemovesPublicInExtensionOfPublicNestedTypeInInternalType() {
+        let input = """
+        struct Foo {
+            public struct Bar {}
+        }
+
+        extension Foo.Bar {
+            public func test() {}
+        }
+        """
+
+        let output = """
+        struct Foo {
+            struct Bar {}
+        }
+
+        extension Foo.Bar {
+            func test() {}
+        }
+        """
+        testFormatting(for: input, output, rule: .redundantPublic, exclude: [.enumNamespaces])
+    }
+
     func testRemovesPublicInExtensionOfNestedInternalType() {
         let input = """
         enum OuterType {