diff --git a/src/parser.js b/src/parser.js
index bcded03..d74ea0f 100644
--- a/src/parser.js
+++ b/src/parser.js
@@ -715,7 +715,12 @@ export default class Parser extends Stream {
                   message: 'EXT-X-DATERANGE with an END-ON-NEXT=YES attribute must not contain DURATION or END-DATE attributes'
                 });
               }
-              if (dateRange.duration && dateRange.endDate) {
+              if (dateRange.duration && dateRange.endDate && !dateRange.startDate) {
+                this.trigger('warn', {
+                  message: 'EXT-X-DATERANGE with DURATION and END-DATE attributes must contain START-DATE attribute'
+                });
+              }
+              if (dateRange.duration && dateRange.endDate && dateRange.startDate) {
                 const startDate = dateRange.startDate;
                 const newDateInSeconds = startDate.getTime() + (dateRange.duration * 1000);