diff --git a/core/src/test/java/io/opentelemetry/android/AndroidResourceTest.kt b/core/src/test/java/io/opentelemetry/android/AndroidResourceTest.kt
index 185bb5478..be1123e03 100644
--- a/core/src/test/java/io/opentelemetry/android/AndroidResourceTest.kt
+++ b/core/src/test/java/io/opentelemetry/android/AndroidResourceTest.kt
@@ -8,20 +8,18 @@ package io.opentelemetry.android
 import android.app.Application
 import android.content.pm.ApplicationInfo
 import android.os.Build
+import io.mockk.MockKAnnotations
+import io.mockk.every
+import io.mockk.impl.annotations.RelaxedMockK
 import io.opentelemetry.android.common.RumConstants
 import io.opentelemetry.sdk.resources.Resource
 import io.opentelemetry.semconv.ServiceAttributes
 import io.opentelemetry.semconv.incubating.DeviceIncubatingAttributes
 import io.opentelemetry.semconv.incubating.OsIncubatingAttributes
 import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Test
-import org.junit.jupiter.api.extension.ExtendWith
-import org.mockito.Answers
-import org.mockito.Mock
-import org.mockito.Mockito
-import org.mockito.junit.jupiter.MockitoExtension
 
-@ExtendWith(MockitoExtension::class)
 internal class AndroidResourceTest {
     private val appName: String = "robotron"
     private val rumSdkVersion: String = BuildConfig.OTEL_ANDROID_VERSION
@@ -34,20 +32,23 @@ internal class AndroidResourceTest {
             Build.VERSION.SDK_INT +
             ")"
 
-    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
+    @RelaxedMockK
     private lateinit var app: Application
 
+    @BeforeEach
+    fun setUp() {
+        MockKAnnotations.init(this)
+    }
+
     @Test
     fun testFullResource() {
-        val appInfo = ApplicationInfo()
-        appInfo.labelRes = 12345
+        val appInfo =
+            ApplicationInfo().apply {
+                labelRes = 12345
+            }
 
-        Mockito
-            .`when`(app.applicationContext.applicationInfo)
-            .thenReturn(appInfo)
-        Mockito
-            .`when`(app.applicationContext.getString(appInfo.labelRes))
-            .thenReturn(appName)
+        every { app.applicationContext.applicationInfo } returns appInfo
+        every { app.applicationContext.getString(appInfo.labelRes) } returns appName
 
         val expected =
             Resource
@@ -58,13 +59,9 @@ internal class AndroidResourceTest {
                         .put(ServiceAttributes.SERVICE_NAME, appName)
                         .put(RumConstants.RUM_SDK_VERSION, rumSdkVersion)
                         .put(DeviceIncubatingAttributes.DEVICE_MODEL_NAME, Build.MODEL)
-                        .put(
-                            DeviceIncubatingAttributes.DEVICE_MODEL_IDENTIFIER,
-                            Build.MODEL,
-                        ).put(
-                            DeviceIncubatingAttributes.DEVICE_MANUFACTURER,
-                            Build.MANUFACTURER,
-                        ).put(OsIncubatingAttributes.OS_NAME, "Android")
+                        .put(DeviceIncubatingAttributes.DEVICE_MODEL_IDENTIFIER, Build.MODEL)
+                        .put(DeviceIncubatingAttributes.DEVICE_MANUFACTURER, Build.MANUFACTURER)
+                        .put(OsIncubatingAttributes.OS_NAME, "Android")
                         .put(OsIncubatingAttributes.OS_TYPE, "linux")
                         .put(OsIncubatingAttributes.OS_VERSION, Build.VERSION.RELEASE)
                         .put(OsIncubatingAttributes.OS_DESCRIPTION, osDescription)
@@ -77,12 +74,8 @@ internal class AndroidResourceTest {
 
     @Test
     fun testProblematicContext() {
-        Mockito
-            .`when`(app.applicationContext.applicationInfo)
-            .thenThrow(SecurityException("cannot do that"))
-        Mockito.`when`(app.applicationContext.resources).thenThrow(
-            SecurityException("boom"),
-        )
+        every { app.applicationContext.applicationInfo } throws SecurityException("cannot do that")
+        every { app.applicationContext.resources } throws SecurityException("boom")
 
         val expected =
             Resource
@@ -93,13 +86,9 @@ internal class AndroidResourceTest {
                         .put(ServiceAttributes.SERVICE_NAME, "unknown_service:android")
                         .put(RumConstants.RUM_SDK_VERSION, rumSdkVersion)
                         .put(DeviceIncubatingAttributes.DEVICE_MODEL_NAME, Build.MODEL)
-                        .put(
-                            DeviceIncubatingAttributes.DEVICE_MODEL_IDENTIFIER,
-                            Build.MODEL,
-                        ).put(
-                            DeviceIncubatingAttributes.DEVICE_MANUFACTURER,
-                            Build.MANUFACTURER,
-                        ).put(OsIncubatingAttributes.OS_NAME, "Android")
+                        .put(DeviceIncubatingAttributes.DEVICE_MODEL_IDENTIFIER, Build.MODEL)
+                        .put(DeviceIncubatingAttributes.DEVICE_MANUFACTURER, Build.MANUFACTURER)
+                        .put(OsIncubatingAttributes.OS_NAME, "Android")
                         .put(OsIncubatingAttributes.OS_TYPE, "linux")
                         .put(OsIncubatingAttributes.OS_VERSION, Build.VERSION.RELEASE)
                         .put(OsIncubatingAttributes.OS_DESCRIPTION, osDescription)