diff --git a/memes.lua b/memes.lua
index e00e06e..c80847b 100644
--- a/memes.lua
+++ b/memes.lua
@@ -547,7 +547,8 @@ local function is_image_link (str)
     if type(str) ~= 'string'      then  return false  end
     if not str:match '^%a+://.+$' then  return false  end
     local headers  =  internet.download_headers(str)
-    return headers['content-type']:match '^image/%a+$'
+    print(headers)
+    return type(headers) == 'table' and headers['content-type']:match '^image/%a+$'
 end
 
 function memes.generate_for_message (user, message)