diff --git a/includes/class-wc-regenerate-images.php b/includes/class-wc-regenerate-images.php
index 741431e38e8..23e4c6f5617 100644
--- a/includes/class-wc-regenerate-images.php
+++ b/includes/class-wc-regenerate-images.php
@@ -66,7 +66,7 @@ class WC_Regenerate_Images {
 
 		$size_settings = wc_get_image_size( $size );
 
-		if ( isset( $imagemeta['sizes'], $imagemeta['sizes'][ $size ] ) ) {
+		if ( is_string( $size ) && isset( $imagemeta['sizes'], $imagemeta['sizes'][ $size ] ) ) {
 			if ( $imagemeta['sizes'][ $size ]['width'] !== $size_settings['width'] || $imagemeta['sizes'][ $size ]['height'] !== $size_settings['height'] ) {
 				$image = self::resize_and_return_image( $attachment_id, $image, $size, $icon );
 			}