diff --git a/inc/compatibilities/otter_blocks.php b/inc/compatibilities/otter_blocks.php
index 81dfecdb..b24e95d5 100644
--- a/inc/compatibilities/otter_blocks.php
+++ b/inc/compatibilities/otter_blocks.php
@@ -7,7 +7,6 @@
  */
 class Optml_otter_blocks extends Optml_compatibility {
 
-
 	/**
 	 * Should we load the integration logic.
 	 *
@@ -39,5 +38,43 @@ function ( $all_watchers ) {
 
 		// Replace the image URL with the optimized one in Otter-generated CSS.
 		add_filter( 'otter_apply_dynamic_image', [ Optml_Main::instance()->manager->url_replacer, 'build_url' ], 99 );
+
+		// Ensure replacer is initialized for Otter REST API routes (where register_hooks isn't called).
+		add_filter( 'rest_pre_dispatch', [ $this, 'maybe_init_replacer_for_rest' ], 10, 3 );
+	}
+
+	/**
+	 * Initialize replacer for Otter REST API routes.
+	 *
+	 * @param mixed            $result  Response to replace the requested version with.
+	 * @param \WP_REST_Server  $server  Server instance.
+	 * @param \WP_REST_Request $request Request used to generate the response.
+	 * @return mixed Unmodified result.
+	 */
+	public function maybe_init_replacer_for_rest( $result, \WP_REST_Server $server, \WP_REST_Request $request ) {
+		$route = $request->get_route();
+
+		// Only initialize for Otter styles REST routes.
+		if ( strpos( $route, '/otter/v1/post_styles' ) === false
+			&& strpos( $route, '/otter/v1/widget_styles' ) === false
+			&& strpos( $route, '/otter/v1/block_styles' ) === false
+		) {
+			return $result;
+		}
+
+		if ( ! did_action( 'optml_replacer_setup' ) ) {
+			do_action( 'optml_replacer_setup' );
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Should we early load the compatibility?
+	 *
+	 * @return bool Whether to load the compatibility early.
+	 */
+	public function should_load_early() {
+		return true;
 	}
 }
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index a002da25..e60e4248 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -1020,6 +1020,12 @@ parameters:
 			count: 1
 			path: inc/compatibilities/metaslider.php
 
+		-
+			message: '#^Method Optml_otter_blocks\:\:maybe_init_replacer_for_rest\(\) has parameter \$request with generic class WP_REST_Request but does not specify its types\: T$#'
+			identifier: missingType.generics
+			count: 1
+			path: inc/compatibilities/otter_blocks.php
+
 		-
 			message: '#^Method Optml_otter_blocks\:\:register\(\) has no return type specified\.$#'
 			identifier: missingType.return