diff --git a/src/java.base/share/classes/sun/text/resources/BreakIteratorRules.java b/src/java.base/share/classes/sun/text/resources/BreakIteratorRules.java
index 4283cd381c8..92bbe58f261 100644
--- a/src/java.base/share/classes/sun/text/resources/BreakIteratorRules.java
+++ b/src/java.base/share/classes/sun/text/resources/BreakIteratorRules.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2007, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -310,7 +310,7 @@ public class BreakIteratorRules extends ListResourceBundle {
               // punctuation" and quotation marks
               + "<start-punctuation>=[:Ps::Pi:\\\"\\\'];"
 
-              // punctuation with may occur at the end of a sentence: "ending punctuation"
+              // punctuation which may occur at the end of a sentence: "ending punctuation"
               // and quotation marks
               + "<end>=[:Pe::Pf:\\\"\\\'];"
 
@@ -323,9 +323,12 @@ public class BreakIteratorRules extends ListResourceBundle {
               // periods, which MAY signal the end of a sentence
               + "<period>=[\\.\uff0e];"
 
+              // comma, which may not occur at the start of a sentence
+              + "<comma>=[\\,];"
+
               // characters that may occur at the beginning of a sentence: basically anything
               // not mentioned above (letters and digits are specifically excluded)
-              + "<sent-start>=[^[:L:<space><start-punctuation><end><digit><term><period>\u2029<ignore>]];"
+              + "<sent-start>=[^[:L:<space><start-punctuation><end><digit><term><period><comma>\u2029<ignore>]];"
 
               // Hindi phrase separator
               + "<danda>=[\u0964\u0965];"
diff --git a/test/jdk/java/text/BreakIterator/BreakIteratorTest.java b/test/jdk/java/text/BreakIterator/BreakIteratorTest.java
index 3c2498de48e..74265a11aee 100644
--- a/test/jdk/java/text/BreakIterator/BreakIteratorTest.java
+++ b/test/jdk/java/text/BreakIterator/BreakIteratorTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,7 +25,7 @@
  * @test
  * @bug 4035266 4052418 4068133 4068137 4068139 4086052 4095322 4097779
  *      4097920 4098467 4111338 4113835 4117554 4143071 4146175 4152117
- *      4152416 4153072 4158381 4214367 4217703 4638433
+ *      4152416 4153072 4158381 4214367 4217703 4638433 8264765
  * @library /java/text/testlib
  * @run main/timeout=2000 BreakIteratorTest
  * @summary test BreakIterator
@@ -746,6 +746,17 @@ public class BreakIteratorTest extends IntlTest
         generalIteratorTest(sentenceBreak, sentenceSelectionData);
     }
 
+    public void TestBug8264765() {
+        Vector<String> sentenceSelectionData = new Vector<String>();
+
+        // Comma should not be regarded as the start of a sentence,
+        // otherwise the backwards rule would break the following sentence.
+        sentenceSelectionData.addElement(
+            "Due to a problem (e.g., software bug), the server is down. ");
+
+        generalIteratorTest(sentenceBreak, sentenceSelectionData);
+    }
+
     public void TestLineBreak() {
         Vector<String> lineSelectionData = new Vector<String>();