diff --git a/sample/build.gradle.kts b/sample/build.gradle.kts
index 173b025..2fe1fae 100644
--- a/sample/build.gradle.kts
+++ b/sample/build.gradle.kts
@@ -9,6 +9,12 @@ kotlin {
     val androidNdkTargets = listOf(androidNativeArm64(), androidNativeArm32(),
         androidNativeX64(), androidNativeX86())
 
+    androidNdkTargets.forEach {
+        it.binaries {
+            sharedLib()
+        }
+    }
+
     sourceSets {
         val commonMain by getting
         val ndkMain by creating {
@@ -66,7 +72,6 @@ repositories {
     mavenLocal()
 }
 
-
 tasks {
     val prepareAndroidNdkSo by creating {
         dependsOn(build)
diff --git a/sample/src/androidMain/jniLibs/arm64-v8a/libsample.so b/sample/src/androidMain/jniLibs/arm64-v8a/libsample.so
index b377ed7..48b3943 100755
Binary files a/sample/src/androidMain/jniLibs/arm64-v8a/libsample.so and b/sample/src/androidMain/jniLibs/arm64-v8a/libsample.so differ
diff --git a/sample/src/androidMain/jniLibs/armeabi-v7a/libsample.so b/sample/src/androidMain/jniLibs/armeabi-v7a/libsample.so
index 2778640..8db47f6 100755
Binary files a/sample/src/androidMain/jniLibs/armeabi-v7a/libsample.so and b/sample/src/androidMain/jniLibs/armeabi-v7a/libsample.so differ
diff --git a/sample/src/androidMain/jniLibs/x86/libsample.so b/sample/src/androidMain/jniLibs/x86/libsample.so
index bbdc925..4edc59b 100755
Binary files a/sample/src/androidMain/jniLibs/x86/libsample.so and b/sample/src/androidMain/jniLibs/x86/libsample.so differ
diff --git a/sample/src/androidMain/jniLibs/x86_64/libsample.so b/sample/src/androidMain/jniLibs/x86_64/libsample.so
index d0a8740..b90afee 100755
Binary files a/sample/src/androidMain/jniLibs/x86_64/libsample.so and b/sample/src/androidMain/jniLibs/x86_64/libsample.so differ
diff --git a/sample/src/androidMain/kotlin/io/github/landrynorris/sample/JniBridge.kt b/sample/src/androidMain/kotlin/io/github/landrynorris/sample/JniBridge.kt
index 4d9a476..51c4278 100644
--- a/sample/src/androidMain/kotlin/io/github/landrynorris/sample/JniBridge.kt
+++ b/sample/src/androidMain/kotlin/io/github/landrynorris/sample/JniBridge.kt
@@ -13,7 +13,7 @@ object JniBridge {
     external fun handleShared(sharedClass: SharedClass): String
     external fun doubleAll(array: DoubleArray): DoubleArray
     external fun callJavaFunction(value: Double)
-    external fun createDataClass(s: String, i: Int, d: Double, doubles: DoubleArray): Any
+    external fun createDataClass(s: String?, i: Int, d: Double, doubles: DoubleArray): Any
     external fun buttonClicked(ptr: Long)
     external fun getText(ptr: Long): String
     external fun createRepository(): Long
diff --git a/sample/src/androidMain/kotlin/io/github/landrynorris/sample/MainActivity.kt b/sample/src/androidMain/kotlin/io/github/landrynorris/sample/MainActivity.kt
index 8fdb5d0..2094934 100644
--- a/sample/src/androidMain/kotlin/io/github/landrynorris/sample/MainActivity.kt
+++ b/sample/src/androidMain/kotlin/io/github/landrynorris/sample/MainActivity.kt
@@ -54,5 +54,13 @@ class MainActivity: AppCompatActivity() {
             if(dataClass.d != d) error("Double wasn't set correctly")
             if(!dataClass.doubles.contentEquals(doubles)) error("Double array wasn't set correctly")
         }
+
+        val dataClassWithNull = JniBridge.createDataClass(null, 0, 0.0, doubleArrayOf())
+        if(dataClassWithNull is DataClass) {
+            if(dataClassWithNull.s != null) error("String wasn't set correctly")
+            if(dataClassWithNull.i != 0) error("Int wasn't set correctly")
+            if(dataClassWithNull.d != 0.0) error("Double wasn't set correctly")
+            if(dataClassWithNull.doubles.isNotEmpty()) error("Double array wasn't set correctly")
+        }
     }
 }
diff --git a/sample/src/commonMain/kotlin/io/github/landrynorris/jni/sample/DataClass.kt b/sample/src/commonMain/kotlin/io/github/landrynorris/jni/sample/DataClass.kt
index 9adbe12..144de3c 100644
--- a/sample/src/commonMain/kotlin/io/github/landrynorris/jni/sample/DataClass.kt
+++ b/sample/src/commonMain/kotlin/io/github/landrynorris/jni/sample/DataClass.kt
@@ -1,3 +1,3 @@
 package io.github.landrynorris.jni.sample
 
-data class DataClass(val s: String, val i: Int, val d: Double, val doubles: DoubleArray)
+data class DataClass(val s: String?, val i: Int, val d: Double, val doubles: DoubleArray)
diff --git a/sample/src/ndkMain/kotlin/io/github/landrynorris/jni/sample/Jni.kt b/sample/src/ndkMain/kotlin/io/github/landrynorris/jni/sample/Jni.kt
index d076689..9d2043a 100644
--- a/sample/src/ndkMain/kotlin/io/github/landrynorris/jni/sample/Jni.kt
+++ b/sample/src/ndkMain/kotlin/io/github/landrynorris/jni/sample/Jni.kt
@@ -111,7 +111,8 @@ fun registerJniNatives(env: CPointer<JNIEnvVar>) {
         }
 
         method("createDataClass") {
-            signature = signature(::createDataClass)
+            signature = Signature(listOf(String, Int, Double, DoubleArray),
+                createSignature("java.lang.Object")).toString()
             function = staticCFunction(::createDataClass)
         }