diff --git a/includes/options/class-amp-options-menu.php b/includes/options/class-amp-options-menu.php
index 7f1746230cc..a9302d10653 100644
--- a/includes/options/class-amp-options-menu.php
+++ b/includes/options/class-amp-options-menu.php
@@ -234,7 +234,7 @@ public function render_theme_support() {
 									sprintf(
 									/* translators: 1: customized AMP query var, 2: default AMP query var */
 										esc_html__( 'Warning: You customized your AMP query var too late. This means that Reader themes will not be available to you. You customized it to be %1$s instead of the default %2$s.', 'amp' ),
-										sprintf( '&#8220;<code>%s</code>&#8221;', esc_html( $amp_slug_customization_watcher->get_customized_slug() ) ),
+										sprintf( '&#8220;<code>%s</code>&#8221;', esc_html( amp_get_slug() ) ),
 										sprintf( '&#8220;<code>%s</code>&#8221;', QueryVars::AMP )
 									)
 								);
@@ -249,7 +249,7 @@ public function render_theme_support() {
 									sprintf(
 									/* translators: 1: customized AMP query var, 2: default AMP query var */
 										esc_html__( 'You customized your query var to be %1$s instead of the default %2$s.', 'amp' ),
-										sprintf( '&#8220;<code>%s</code>&#8221;', esc_html( $amp_slug_customization_watcher->get_customized_slug() ) ),
+										sprintf( '&#8220;<code>%s</code>&#8221;', esc_html( amp_get_slug() ) ),
 										sprintf( '&#8220;<code>%s</code>&#8221;', QueryVars::AMP )
 									)
 								);
diff --git a/src/AmpSlugCustomizationWatcher.php b/src/AmpSlugCustomizationWatcher.php
index a85285b2317..90a051a4dea 100644
--- a/src/AmpSlugCustomizationWatcher.php
+++ b/src/AmpSlugCustomizationWatcher.php
@@ -17,13 +17,6 @@
  */
 final class AmpSlugCustomizationWatcher implements Service, Registerable {
 
-	/**
-	 * The slug (query var) that was customized.
-	 *
-	 * @var string|null
-	 */
-	protected $customized_slug = null;
-
 	/**
 	 * Whether the slug was customized early (at plugins_loaded action, priority 8).
 	 *
@@ -65,26 +58,6 @@ public function did_customize_late() {
 		return $this->is_customized_late;
 	}
 
-	/**
-	 * Whether the slug was customized.
-	 *
-	 * @return bool
-	 */
-	public function did_customize_slug() {
-		return null !== $this->customized_slug;
-	}
-
-	/**
-	 * Get the customized slug.
-	 *
-	 * Returns null if it was not customized.
-	 *
-	 * @return string|null
-	 */
-	public function get_customized_slug() {
-		return $this->customized_slug;
-	}
-
 	/**
 	 * Peek at the customized slug.
 	 *
@@ -93,7 +66,7 @@ public function get_customized_slug() {
 	 *
 	 * @return string Query var.
 	 */
-	public function peek_customized_slug() {
+	protected function peek_customized_slug() {
 		return amp_get_slug( false );
 	}
 
@@ -108,7 +81,6 @@ public function peek_customized_slug() {
 	public function determine_early_customization() {
 		$slug = $this->peek_customized_slug();
 		if ( QueryVars::AMP !== $slug ) {
-			$this->customized_slug     = $slug;
 			$this->is_customized_early = true;
 		} else {
 			add_action( 'after_setup_theme', [ $this, 'determine_late_customization' ], 4 );
@@ -132,7 +104,6 @@ public function determine_early_customization() {
 	public function determine_late_customization() {
 		$slug = $this->peek_customized_slug();
 		if ( QueryVars::AMP !== $slug ) {
-			$this->customized_slug    = $slug;
 			$this->is_customized_late = true;
 		}
 	}