diff --git a/CHANGES.txt b/CHANGES.txt
index e607a0c106..7fb8cd8dac 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -292,6 +292,9 @@ Trunk (unreleased changes)
     HADOOP-7011.  Fix KerberosName.main() to not throw an NPE.
     (Aaron T. Myers via tomwhite)
 
+    HADOOP-6975.  Integer overflow in S3InputStream for blocks > 2GB.
+    (Patrick Kling via tomwhite)
+
 Release 0.21.1 - Unreleased
 
   IMPROVEMENTS
diff --git a/src/java/org/apache/hadoop/fs/s3/S3InputStream.java b/src/java/org/apache/hadoop/fs/s3/S3InputStream.java
index 302174bf7e..ec3f150234 100644
--- a/src/java/org/apache/hadoop/fs/s3/S3InputStream.java
+++ b/src/java/org/apache/hadoop/fs/s3/S3InputStream.java
@@ -128,7 +128,7 @@ public synchronized int read(byte buf[], int off, int len) throws IOException {
       if (pos > blockEnd) {
         blockSeekTo(pos);
       }
-      int realLen = Math.min(len, (int) (blockEnd - pos + 1));
+      int realLen = (int) Math.min((long) len, (blockEnd - pos + 1L));
       int result = blockStream.read(buf, off, realLen);
       if (result >= 0) {
         pos += result;