diff --git a/includes/class-modal-checkout.php b/includes/class-modal-checkout.php
index bec59c382..cf456fac5 100644
--- a/includes/class-modal-checkout.php
+++ b/includes/class-modal-checkout.php
@@ -965,6 +965,21 @@ public static function is_modal_checkout() {
 		if ( ! $is_modal_checkout && isset( $_REQUEST['post_data'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended
 			$is_modal_checkout = strpos( $_REQUEST['post_data'], 'modal_checkout=1' ) !== false; // phpcs:ignore WordPress.Security.NonceVerification.Recommended, WordPress.Security.ValidatedSanitizedInput.MissingUnslash, WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
 		}
+
+		// Express checkout payment requests are separate requests, so they won't have the modal checkout flag. We'll have to check the HTTP_REFERER insteaad.
+		$payment_request_type = filter_input( INPUT_POST, 'payment_request_type', FILTER_SANITIZE_FULL_SPECIAL_CHARS );
+		$is_express_checkout  = ! empty( $payment_request_type ) && in_array( $payment_request_type, [ 'apple_pay', 'google_pay', 'payment_request_api' ], true ); // Validate payment request types: https://github.com/woocommerce/woocommerce-gateway-stripe/blob/develop/includes/payment-methods/class-wc-stripe-payment-request.php#L529-L548.
+		if ( $is_express_checkout ) {
+			$referrer = isset( $_SERVER['HTTP_REFERER'] ) ? \esc_url_raw( \wp_unslash( $_SERVER['HTTP_REFERER'] ) ) : false; // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
+			if ( $referrer ) {
+				$referrer_query = \wp_parse_url( $referrer, PHP_URL_QUERY );
+				\wp_parse_str( $referrer_query, $referrer_query_params );
+				if ( isset( $referrer_query_params['modal_checkout'] ) && $referrer_query_params['modal_checkout'] ) {
+					$is_modal_checkout = true;
+				}
+			}
+		}
+
 		return $is_modal_checkout;
 	}