diff --git a/src/i18n-module.php b/src/i18n-module.php
index 0fdd647..d114167 100644
--- a/src/i18n-module.php
+++ b/src/i18n-module.php
@@ -276,7 +276,7 @@ public function promo() {
 
 			echo '<div>';
 			echo '<h2>' . sprintf( __( 'Translation of %s', $this->textdomain ), $this->plugin_name ) . '</h2>';
-			if ( isset( $this->glotpress_logo ) && '' != $this->glotpress_logo ) {
+			if ( isset( $this->glotpress_logo ) && is_string( $this->glotpress_logo ) && '' !== $this->glotpress_logo ) {
 				echo '<a href="' . esc_url( $this->register_url ) . '"><img class="alignright" style="margin:0 5px 5px 5px;max-width:200px;" src="' . esc_url( $this->glotpress_logo ) . '" alt="' . esc_attr( $this->glotpress_name ) . '"/></a>';
 			}
 			echo $message;