diff --git a/validators/tsv.js b/validators/tsv.js
index 3d1f28180..37ca386f0 100644
--- a/validators/tsv.js
+++ b/validators/tsv.js
@@ -86,21 +86,19 @@ var TSV = function TSV (file, contents, fileList, callback) {
 
     // events.tsv
     if (file.name.endsWith('_events.tsv')) {
-        if (headers[0] !== "onset"){
+        if ((headers.length == 0) || (headers[0] !== "onset")){
             issues.push(new Issue({
                 file: file,
                 evidence: headers,
                 line: 1,
-                character: rows[0].indexOf(headers[0]),
                 code: 20
             }));
         }
-        if (headers[1].trim() !== "duration"){
+        if ((headers.length == 1) || (headers[1].trim() !== "duration")){
             issues.push(new Issue({
                 file: file,
                 evidence: headers,
                 line: 1,
-                character: rows[0].indexOf(headers[1]),
                 code: 21
             }));
         }