diff --git a/stripe/src/main/java/com/stripe/android/view/CardInputWidget.kt b/stripe/src/main/java/com/stripe/android/view/CardInputWidget.kt
index 415d25559fc..d612f9a29f2 100644
--- a/stripe/src/main/java/com/stripe/android/view/CardInputWidget.kt
+++ b/stripe/src/main/java/com/stripe/android/view/CardInputWidget.kt
@@ -381,24 +381,31 @@ class CardInputWidget @JvmOverloads constructor(
     /**
      * Expose a text watcher to receive updates when the card number is changed.
      */
-    fun setCardNumberTextWatcher(cardNumberTextWatcher: TextWatcher?) {
+    override fun setCardNumberTextWatcher(cardNumberTextWatcher: TextWatcher?) {
         cardNumberEditText.addTextChangedListener(cardNumberTextWatcher)
     }
 
     /**
      * Expose a text watcher to receive updates when the expiry date is changed.
      */
-    fun setExpiryDateTextWatcher(expiryDateTextWatcher: TextWatcher?) {
+    override fun setExpiryDateTextWatcher(expiryDateTextWatcher: TextWatcher?) {
         expiryDateEditText.addTextChangedListener(expiryDateTextWatcher)
     }
 
     /**
      * Expose a text watcher to receive updates when the cvc number is changed.
      */
-    fun setCvcNumberTextWatcher(cvcNumberTextWatcher: TextWatcher?) {
+    override fun setCvcNumberTextWatcher(cvcNumberTextWatcher: TextWatcher?) {
         cvcNumberEditText.addTextChangedListener(cvcNumberTextWatcher)
     }
 
+    /**
+     * Expose a text watcher to receive updates when the cvc number is changed.
+     */
+    override fun setPostalCodeTextWatcher(postalCodeTextWatcher: TextWatcher?) {
+        postalCodeEditText.addTextChangedListener(postalCodeTextWatcher)
+    }
+
     /**
      * Override of [View.isEnabled] that returns `true` only
      * if all three sub-controls are enabled.
diff --git a/stripe/src/main/java/com/stripe/android/view/CardMultilineWidget.kt b/stripe/src/main/java/com/stripe/android/view/CardMultilineWidget.kt
index 814d57027d7..14ab6d445d1 100644
--- a/stripe/src/main/java/com/stripe/android/view/CardMultilineWidget.kt
+++ b/stripe/src/main/java/com/stripe/android/view/CardMultilineWidget.kt
@@ -415,28 +415,28 @@ class CardMultilineWidget @JvmOverloads constructor(
     /**
      * Expose a text watcher to receive updates when the card number is changed.
      */
-    fun setCardNumberTextWatcher(cardNumberTextWatcher: TextWatcher?) {
+    override fun setCardNumberTextWatcher(cardNumberTextWatcher: TextWatcher?) {
         cardNumberEditText.addTextChangedListener(cardNumberTextWatcher)
     }
 
     /**
      * Expose a text watcher to receive updates when the expiry date is changed.
      */
-    fun setExpiryDateTextWatcher(expiryDateTextWatcher: TextWatcher?) {
+    override fun setExpiryDateTextWatcher(expiryDateTextWatcher: TextWatcher?) {
         expiryDateEditText.addTextChangedListener(expiryDateTextWatcher)
     }
 
     /**
      * Expose a text watcher to receive updates when the cvc number is changed.
      */
-    fun setCvcNumberTextWatcher(cvcNumberTextWatcher: TextWatcher?) {
+    override fun setCvcNumberTextWatcher(cvcNumberTextWatcher: TextWatcher?) {
         cvcEditText.addTextChangedListener(cvcNumberTextWatcher)
     }
 
     /**
      * Expose a text watcher to receive updates when the cvc number is changed.
      */
-    fun setPostalCodeTextWatcher(postalCodeTextWatcher: TextWatcher?) {
+    override fun setPostalCodeTextWatcher(postalCodeTextWatcher: TextWatcher?) {
         postalCodeEditText.addTextChangedListener(postalCodeTextWatcher)
     }
 
diff --git a/stripe/src/main/java/com/stripe/android/view/CardWidget.kt b/stripe/src/main/java/com/stripe/android/view/CardWidget.kt
index 304f37ae190..143e383cfc7 100644
--- a/stripe/src/main/java/com/stripe/android/view/CardWidget.kt
+++ b/stripe/src/main/java/com/stripe/android/view/CardWidget.kt
@@ -1,5 +1,6 @@
 package com.stripe.android.view
 
+import android.text.TextWatcher
 import androidx.annotation.IntRange
 import com.stripe.android.model.Card
 import com.stripe.android.model.PaymentMethodCreateParams
@@ -28,6 +29,26 @@ internal interface CardWidget {
 
     fun setCardInputListener(listener: CardInputListener?)
 
+    /**
+     * Expose a text watcher to receive updates when the card number is changed.
+     */
+    fun setCardNumberTextWatcher(cardNumberTextWatcher: TextWatcher?)
+
+    /**
+     * Expose a text watcher to receive updates when the expiry date is changed.
+     */
+    fun setExpiryDateTextWatcher(expiryDateTextWatcher: TextWatcher?)
+
+    /**
+     * Expose a text watcher to receive updates when the cvc number is changed.
+     */
+    fun setCvcNumberTextWatcher(cvcNumberTextWatcher: TextWatcher?)
+
+    /**
+     * Expose a text watcher to receive updates when the cvc number is changed.
+     */
+    fun setPostalCodeTextWatcher(postalCodeTextWatcher: TextWatcher?)
+
     fun setCardHint(cardHint: String)
 
     fun clear()