diff --git a/lib/text/text_utils.js b/lib/text/text_utils.js
index c4770d795b..eebb7a8871 100644
--- a/lib/text/text_utils.js
+++ b/lib/text/text_utils.js
@@ -148,7 +148,7 @@ shaka.text.Utils = class {
    */
   static getCuesToFlatten(cues, parentCue) {
     const result = [];
-    for (const cue of cues) {
+    for (const cue of shaka.text.Utils.removeDuplicates(cues)) {
       if (cue.isContainer) {
         // Recurse to find the actual text payload cues.
         result.push(...shaka.text.Utils.getCuesToFlatten(cue.nestedCues, cue));
@@ -162,4 +162,20 @@ shaka.text.Utils = class {
     }
     return result;
   }
+
+  /**
+   * @param {!Array.<!shaka.text.Cue>} cues
+   * @return {!Array.<!shaka.text.Cue>}
+   */
+  static removeDuplicates(cues) {
+    const uniqueCues = [];
+    for (const cue of cues) {
+      const isValid = !uniqueCues.some(
+          (existingCue) => shaka.text.Cue.equal(cue, existingCue));
+      if (isValid) {
+        uniqueCues.push(cue);
+      }
+    }
+    return uniqueCues;
+  }
 };
diff --git a/lib/text/ui_text_displayer.js b/lib/text/ui_text_displayer.js
index 7b33c48416..1ac76291c3 100644
--- a/lib/text/ui_text_displayer.js
+++ b/lib/text/ui_text_displayer.js
@@ -11,6 +11,7 @@ goog.require('goog.asserts');
 goog.require('shaka.Deprecate');
 goog.require('shaka.text.Cue');
 goog.require('shaka.text.CueRegion');
+goog.require('shaka.text.Utils');
 goog.require('shaka.util.Dom');
 goog.require('shaka.util.EventManager');
 goog.require('shaka.util.Timer');
@@ -156,7 +157,7 @@ shaka.text.UITextDisplayer = class {
     // list growing during the comparisons for duplicate cues.
     // See: https://github.com/shaka-project/shaka-player/issues/3018
     const cuesList = [...this.cues_];
-    for (const cue of cues) {
+    for (const cue of shaka.text.Utils.removeDuplicates(cues)) {
       // When a VTT cue spans a segment boundary, the cue will be duplicated
       // into two segments.
       // To avoid displaying duplicate cues, if the current cue list already
diff --git a/test/text/ui_text_displayer_unit.js b/test/text/ui_text_displayer_unit.js
index ddddf3b00d..b8262374c5 100644
--- a/test/text/ui_text_displayer_unit.js
+++ b/test/text/ui_text_displayer_unit.js
@@ -412,8 +412,8 @@ describe('UITextDisplayer', () => {
     // be created.
     const cues = [
       new shaka.text.Cue(0, 100, ''),
-      new shaka.text.Cue(0, 100, ''),
-      new shaka.text.Cue(0, 100, ''),
+      new shaka.text.Cue(0, 200, ''),
+      new shaka.text.Cue(0, 300, ''),
     ];
     for (const cue of cues) {
       cue.displayAlign = shaka.text.Cue.displayAlign.CENTER;
@@ -567,8 +567,8 @@ describe('UITextDisplayer', () => {
     // be created.
     const firstBatchOfCues = [
       new shaka.text.Cue(0, 100, ''),
-      new shaka.text.Cue(0, 100, ''),
-      new shaka.text.Cue(0, 100, ''),
+      new shaka.text.Cue(0, 200, ''),
+      new shaka.text.Cue(0, 300, ''),
     ];
     for (const cue of firstBatchOfCues) {
       cue.displayAlign = shaka.text.Cue.displayAlign.CENTER;
@@ -578,8 +578,8 @@ describe('UITextDisplayer', () => {
     // Another batch for the other region
     const secondBatchOfCues = [
       new shaka.text.Cue(0, 100, ''),
-      new shaka.text.Cue(0, 100, ''),
-      new shaka.text.Cue(0, 100, ''),
+      new shaka.text.Cue(0, 200, ''),
+      new shaka.text.Cue(0, 300, ''),
     ];
     for (const cue of secondBatchOfCues) {
       cue.displayAlign = shaka.text.Cue.displayAlign.CENTER;