diff --git a/src/main/java/org/apache/commons/io/input/buffer/CircularBufferInputStream.java b/src/main/java/org/apache/commons/io/input/buffer/CircularBufferInputStream.java
index 2432cd5..e59b60e 100644
--- a/src/main/java/org/apache/commons/io/input/buffer/CircularBufferInputStream.java
+++ b/src/main/java/org/apache/commons/io/input/buffer/CircularBufferInputStream.java
@@ -28,6 +28,8 @@
 /**
  * Implements a buffered input stream, which is internally based on a {@link CircularByteBuffer}. Unlike the
  * {@link java.io.BufferedInputStream}, this one doesn't need to reallocate byte arrays internally.
+ *
+ * @since 2.7
  */
 public class CircularBufferInputStream extends FilterInputStream {
 
diff --git a/src/main/java/org/apache/commons/io/input/buffer/CircularByteBuffer.java b/src/main/java/org/apache/commons/io/input/buffer/CircularByteBuffer.java
index f8e6dd3..6ad14b3 100644
--- a/src/main/java/org/apache/commons/io/input/buffer/CircularByteBuffer.java
+++ b/src/main/java/org/apache/commons/io/input/buffer/CircularByteBuffer.java
@@ -26,6 +26,8 @@
  * from the buffer takes place at the same time than writing to. Such is the
  * case, for example, when using the buffer within a filtering input stream,
  * like the {@link CircularBufferInputStream}.
+ *
+ * @since 2.7
  */
 public class CircularByteBuffer {
     private final byte[] buffer;
diff --git a/src/main/java/org/apache/commons/io/input/buffer/PeekableInputStream.java b/src/main/java/org/apache/commons/io/input/buffer/PeekableInputStream.java
index 086ac9d..b70b5ef 100644
--- a/src/main/java/org/apache/commons/io/input/buffer/PeekableInputStream.java
+++ b/src/main/java/org/apache/commons/io/input/buffer/PeekableInputStream.java
@@ -25,6 +25,8 @@
 /**
  * Implements a buffered input stream, which allows to peek into the buffers first bytes. This comes in handy when
  * manually implementing scanners, lexers, parsers, and the like.
+ *
+ * @since 2.7
  */
 public class PeekableInputStream extends CircularBufferInputStream {