diff --git a/src/Umbraco.Web/umbraco.presentation/macro.cs b/src/Umbraco.Web/umbraco.presentation/macro.cs
index 4e492b0b0e..6e26718514 100644
--- a/src/Umbraco.Web/umbraco.presentation/macro.cs
+++ b/src/Umbraco.Web/umbraco.presentation/macro.cs
@@ -1496,7 +1496,7 @@ namespace umbraco
             IDictionaryEnumerator ide = attributes.GetEnumerator();
             while (ide.MoveNext())
             {
-                div += string.Format("umb_{0}=\"{1}\" ", ide.Key, encodeMacroAttribute(ide.Value.ToString()));
+                div += string.Format("umb_{0}=\"{1}\" ", ide.Key, encodeMacroAttribute((ide.Value ?? string.Empty).ToString()));
             }
 
             div += "ismacro=\"true\" onresizestart=\"return false;\" umbVersionId=\"" + versionId +
@@ -1559,7 +1559,7 @@ namespace umbraco
                 string querystring = "umbPageId=" + PageID + "&umbVersionId=" + PageVersion;
                 IDictionaryEnumerator ide = attributes.GetEnumerator();
                 while (ide.MoveNext())
-                    querystring += "&umb_" + ide.Key + "=" + HttpContext.Current.Server.UrlEncode(ide.Value.ToString());
+                    querystring += "&umb_" + ide.Key + "=" + HttpContext.Current.Server.UrlEncode((ide.Value ?? string.Empty).ToString()));
 
                 // Create a new 'HttpWebRequest' Object to the mentioned URL.
                 string retVal = string.Empty;