diff --git a/core/SSViewer.php b/core/SSViewer.php
index c060d638b..af033bebc 100755
--- a/core/SSViewer.php
+++ b/core/SSViewer.php
@@ -159,7 +159,7 @@ class SSViewer {
 			}
 		}
 		
-		if(substr((string) $templateList,-3) == '.ss') {
+		if(is_string($templateList) && substr((string) $templateList,-3) == '.ss') {
 			$this->chosenTemplates['main'] = $templateList;
 		} else {
 			if(!is_array($templateList)) $templateList = array($templateList);