diff --git a/example/src/androidTestDebug/java/com/stripe/example/activity/AddFpxPaymentMethodTest.kt b/example/src/androidTestDebug/java/com/stripe/example/activity/AddFpxPaymentMethodTest.kt
index 8742077a038..beccc09596f 100644
--- a/example/src/androidTestDebug/java/com/stripe/example/activity/AddFpxPaymentMethodTest.kt
+++ b/example/src/androidTestDebug/java/com/stripe/example/activity/AddFpxPaymentMethodTest.kt
@@ -12,8 +12,6 @@ import androidx.test.ext.junit.rules.activityScenarioRule
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.filters.LargeTest
 import com.stripe.android.CustomerSession
-import com.stripe.android.EphemeralKeyProvider
-import com.stripe.android.EphemeralKeyUpdateListener
 import com.stripe.example.R
 import org.junit.Before
 import org.junit.Rule
@@ -32,12 +30,8 @@ class AddFpxPaymentMethodTest {
     fun setup() {
         CustomerSession.initCustomerSession(
             context,
-            object : EphemeralKeyProvider {
-                override fun createEphemeralKey(
-                    apiVersion: String,
-                    keyUpdateListener: EphemeralKeyUpdateListener
-                ) {
-                }
+            ephemeralKeyProvider = { _, _ ->
+                // noop
             }
         )
     }
diff --git a/example/src/main/java/com/stripe/example/ExampleApplication.kt b/example/src/main/java/com/stripe/example/ExampleApplication.kt
index 1698de5f16e..b456c62d5bf 100644
--- a/example/src/main/java/com/stripe/example/ExampleApplication.kt
+++ b/example/src/main/java/com/stripe/example/ExampleApplication.kt
@@ -51,6 +51,6 @@ class ExampleApplication : Application() {
     }
 
     private companion object {
-        private val IS_PENALTY_DEATH_ENABLED = false
+        private const val IS_PENALTY_DEATH_ENABLED = false
     }
 }
diff --git a/stripe/src/main/java/com/stripe/android/EphemeralKeyProvider.kt b/stripe/src/main/java/com/stripe/android/EphemeralKeyProvider.kt
index 3b81a5a7fb4..f286bbfec04 100644
--- a/stripe/src/main/java/com/stripe/android/EphemeralKeyProvider.kt
+++ b/stripe/src/main/java/com/stripe/android/EphemeralKeyProvider.kt
@@ -6,7 +6,7 @@ import androidx.annotation.Size
  * Represents an object that can call to a server and create
  * [EphemeralKeys][EphemeralKey].
  */
-interface EphemeralKeyProvider {
+fun interface EphemeralKeyProvider {
 
     /**
      * When called, talks to a client server that then communicates with Stripe's servers to