diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8850263a8..a2e1cdec5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ CHANGELOG
 * @hartman added default print styling ([view](https://github.com/videojs/video.js/pull/3304))
 * @ldayananda updated videojs to not do anything if no src is set ([view](https://github.com/videojs/video.js/pull/3378))
 * @nickygerritsen removed unused tracks when changing sources. Fixes #3000 ([view](https://github.com/videojs/video.js/pull/3002))
+* @vit-koumar updated Flash tech to return Infinity from duration instead of -1 ([view](https://github.com/videojs/video.js/pull/3128))
 
 --------------------
 
diff --git a/src/js/tech/flash.js b/src/js/tech/flash.js
index 11bb2ceff..8bb2d31e3 100644
--- a/src/js/tech/flash.js
+++ b/src/js/tech/flash.js
@@ -229,6 +229,20 @@ class Flash extends Tech {
     }
   }
 
+  /**
+   * Get media duration
+   *
+   * @returns {Number} Media duration
+   */
+  duration() {
+    if (this.readyState() === 0) {
+      return NaN;
+    } else {
+      let duration = this.el_.vjs_getProperty('duration');
+      return duration >= 0 ? duration : Infinity;
+    }
+  }
+
   /**
    * Load media into player
    *
@@ -312,7 +326,7 @@ class Flash extends Tech {
 // Create setters and getters for attributes
 const _api = Flash.prototype;
 const _readWrite = 'rtmpConnection,rtmpStream,preload,defaultPlaybackRate,playbackRate,autoplay,loop,mediaGroup,controller,controls,volume,muted,defaultMuted'.split(',');
-const _readOnly = 'networkState,readyState,initialTime,duration,startOffsetTime,paused,ended,videoWidth,videoHeight'.split(',');
+const _readOnly = 'networkState,readyState,initialTime,startOffsetTime,paused,ended,videoWidth,videoHeight'.split(',');
 
 function _createSetter(attr){
   var attrUpper = attr.charAt(0).toUpperCase() + attr.slice(1);
diff --git a/test/unit/tech/flash.test.js b/test/unit/tech/flash.test.js
index eadab9f93..229d78911 100644
--- a/test/unit/tech/flash.test.js
+++ b/test/unit/tech/flash.test.js
@@ -197,6 +197,33 @@ test('play after ended seeks to the beginning', function() {
   equal(seeks[0], 0, 'seeked to the beginning');
 });
 
+test('duration returns NaN, Infinity or duration according to the HTML standard', function() {
+  let duration = Flash.prototype.duration;
+  let mockedDuration = -1;
+  let mockedReadyState = 0;
+  let result;
+  let mockFlash = {
+    el_: {
+      vjs_getProperty() {
+        return mockedDuration;
+      }
+    },
+    readyState: function() {
+      return mockedReadyState;
+    }
+  };
+  result = duration.call(mockFlash);
+  ok(Number.isNaN(result), 'duration returns NaN when readyState equals 0');
+
+  mockedReadyState = 1;
+  result = duration.call(mockFlash);
+  ok(!Number.isFinite(result), 'duration returns Infinity when duration property is less then 0');
+
+  mockedDuration = 1;
+  result = duration.call(mockFlash);
+  equal(result, 1, 'duration returns duration property when readeyState and duration property are both higher than 0');
+});
+
 // fake out the <object> interaction but leave all the other logic intact
 class MockFlash extends Flash {
   constructor() {