diff --git a/Sources/SkipBridge/AnyDynamicObject.swift b/Sources/SkipBridge/AnyDynamicObject.swift
index 27abde3..83021b4 100644
--- a/Sources/SkipBridge/AnyDynamicObject.swift
+++ b/Sources/SkipBridge/AnyDynamicObject.swift
@@ -40,6 +40,11 @@ open class AnyDynamicObject: JObjectProtocol, JConvertible {
         }
     }
 
+    /// Cast this instance to a generated `AnyDynamicObject` subclass type.
+    public func `as`<T: AnyDynamicObject>(_ type: T.Type) throws -> T {
+        return try T(for: object.ptr)
+    }
+
     public subscript(dynamicMember member: String) -> Bool {
         get {
             jniContext {
diff --git a/Sources/SkipBridgeToKotlinSamples/Samples.swift b/Sources/SkipBridgeToKotlinSamples/Samples.swift
index 99fd525..e8bf9ba 100644
--- a/Sources/SkipBridgeToKotlinSamples/Samples.swift
+++ b/Sources/SkipBridgeToKotlinSamples/Samples.swift
@@ -132,6 +132,12 @@ public class SwiftClass {
     }
 }
 
+extension SwiftClass {
+    public func swiftExtensionFunc(_ i: Int) -> Int {
+        return i
+    }
+}
+
 public final class SwiftSubclass: SwiftClass {
     public var stringVar: String
 
@@ -150,6 +156,10 @@ public final class SwiftHelperClass: SwiftProtocol, Comparable, Identifiable {
     public init() {
     }
 
+    public init(string: String?) throws {
+        self.stringVar = string!
+    }
+
     public func stringValue() -> String {
         return stringVar
     }
diff --git a/Sources/SkipBridgeToSwiftSamples/Samples.swift b/Sources/SkipBridgeToSwiftSamples/Samples.swift
index b3649a3..b8d84e2 100644
--- a/Sources/SkipBridgeToSwiftSamples/Samples.swift
+++ b/Sources/SkipBridgeToSwiftSamples/Samples.swift
@@ -60,6 +60,9 @@ public var kotlinInnerClassVar = KotlinHelperClass.Inner()
 public var kotlinSwiftClassVar = SwiftHelperClass()
 public var kotlinAnyVar: Any = "a"
 public var kotlinAnyHashableVar: AnyHashable = 1
+#if os(Android) || ROBOLECTRIC
+public var kotlinJavaTypeVar: java.util.Date = java.util.Date()
+#endif
 
 // MARK: Global optional vars
 
@@ -134,6 +137,12 @@ public class KotlinClass {
     }
 }
 
+extension KotlinClass {
+    public func kotlinExtensionFunc(_ i: Int) -> Int {
+        return i
+    }
+}
+
 public final class KotlinSubclass: KotlinClass {
     public var stringVar: String
 
diff --git a/Sources/SkipBridgeToSwiftSamplesTestsSupport/TestsSupport.swift b/Sources/SkipBridgeToSwiftSamplesTestsSupport/TestsSupport.swift
index d1b3d3a..6e645dd 100644
--- a/Sources/SkipBridgeToSwiftSamplesTestsSupport/TestsSupport.swift
+++ b/Sources/SkipBridgeToSwiftSamplesTestsSupport/TestsSupport.swift
@@ -5,6 +5,7 @@
 // as published by the Free Software Foundation https://fsf.org
 
 import Foundation
+import SkipBridge
 import SkipBridgeToSwiftSamples
 import SkipBridgeToSwiftSamplesHelpers
 
@@ -181,6 +182,27 @@ public func testSupport_kotlinAnyHashableVar_kotlinClass(value: String) -> Strin
     return (kotlinAnyHashableVar as? KotlinHelperClass)?.stringVar
 }
 
+public func testSupport_kotlinJavaTypeVar() -> String? {
+    #if os(Android) || ROBOLECTRIC
+    guard kotlinJavaTypeVar is AnyDynamicObject else {
+        return "kotlinJavaTypeVar is AnyDynamicObject"
+    }
+    let time: Int64 = kotlinJavaTypeVar.time
+    guard time > 0 else {
+        return "time > 0"
+    }
+    let date = try! AnyDynamicObject(className: "java.util.Date", 999)
+    kotlinJavaTypeVar = date
+    let time2: Int64 = kotlinJavaTypeVar.time
+    guard time2 == 999 else {
+        return "time2 == 999"
+    }
+    return nil
+    #else
+    return nil
+    #endif
+}
+
 public func testSupport_kotlinOptionalBoolVar(value: Bool?) -> Bool? {
     kotlinOptionalBoolVar = value
     return kotlinOptionalBoolVar
@@ -334,6 +356,11 @@ public func testSupport_kotlinClassComparable(lhs: String, rhs: String) -> Bool
     return lhsHelper < rhsHelper
 }
 
+public func testSupport_kotlinExtension(value: Int) -> Int {
+    let cls = KotlinClass()
+    return cls.kotlinExtensionFunc(value)
+}
+
 public func testSupport_kotlinSubclass() -> String? {
     let sub = KotlinSubclass(string: "sub")
     sub.intVar = 100
diff --git a/Tests/SkipBridgeToKotlinSamplesTests/BridgeToKotlinSamplesTests.swift b/Tests/SkipBridgeToKotlinSamplesTests/BridgeToKotlinSamplesTests.swift
index 095224d..adda12a 100644
--- a/Tests/SkipBridgeToKotlinSamplesTests/BridgeToKotlinSamplesTests.swift
+++ b/Tests/SkipBridgeToKotlinSamplesTests/BridgeToKotlinSamplesTests.swift
@@ -280,6 +280,11 @@ final class BridgeToKotlinTests: XCTestCase {
         XCTAssertFalse(lhs < rhs)
     }
 
+    public func testSwiftExtension() {
+        let cls = SwiftClass()
+        XCTAssertEqual(100, cls.swiftExtensionFunc(100))
+    }
+
     public func testSwiftSubclass() {
         let sub = SwiftSubclass(string: "sub")
         sub.intVar = 100
diff --git a/Tests/SkipBridgeToSwiftSamplesTestsSupportTests/BridgeToSwiftSamplesTests.swift b/Tests/SkipBridgeToSwiftSamplesTestsSupportTests/BridgeToSwiftSamplesTests.swift
index 2a6b787..7a5d4eb 100644
--- a/Tests/SkipBridgeToSwiftSamplesTestsSupportTests/BridgeToSwiftSamplesTests.swift
+++ b/Tests/SkipBridgeToSwiftSamplesTestsSupportTests/BridgeToSwiftSamplesTests.swift
@@ -84,6 +84,10 @@ final class BridgeToSwiftTests: XCTestCase {
         XCTAssertEqual(testSupport_kotlinAnyHashableVar_kotlinClass(value: "ss"), "ss")
     }
 
+    func testJavaTypeVar() {
+        XCTAssertNil(testSupport_kotlinJavaTypeVar())
+    }
+
     func testAnyVarContainerValues() {
         let anyArray = testSupport_kotlinAnyVar(value: ["a", 2, 3.0]) as? [Any]
         guard let anyArray else {
@@ -192,7 +196,11 @@ final class BridgeToSwiftTests: XCTestCase {
         XCTAssertFalse(testSupport_kotlinClassComparable(lhs: "bbb", rhs: "aaa"))
     }
 
-    public func testKotlinSubclass() {
+    func testKotlinExtension() {
+        XCTAssertEqual(100, testSupport_kotlinExtension(value: 100))
+    }
+
+    func testKotlinSubclass() {
         XCTAssertNil(testSupport_kotlinSubclass())
     }