diff --git a/mu-plugin/plausible-proxy-speed-module.php b/mu-plugin/plausible-proxy-speed-module.php
index 41d59f1..32c6bd1 100644
--- a/mu-plugin/plausible-proxy-speed-module.php
+++ b/mu-plugin/plausible-proxy-speed-module.php
@@ -4,7 +4,7 @@
  * Description: Speeds up Plausible Analytics' proxy for avoiding ad blockers.
  * Plugin URI: https://plausible.io
  * Author: Plausible HQ
- * Version: 1.0.1
+ * Version: 1.0.2
  * Author URI: https://plausible.io
  *
  * Text Domain: plausible-analytics
@@ -68,6 +68,17 @@ private function is_proxy_request() {
 			return false;
 		}
 
+		/**
+		 * @see   rest_url() requires $wp_rewrite to be set. If it's not set yet, just assume this isn't a proxy request.
+		 *
+		 * @since v1.0.2
+		 */
+		global $wp_rewrite;
+
+		if ( $wp_rewrite === null ) {
+			return false;
+		}
+
 		$expected = function_exists( 'rest_url' )
 			? untrailingslashit( (string) wp_parse_url( rest_url( trim( $namespace, '/' ) ), PHP_URL_PATH ) )
 			: '/wp-json/' . trim( $namespace, '/' );