diff --git a/src/main/java/org/apache/commons/lang3/mutable/MutableBoolean.java b/src/main/java/org/apache/commons/lang3/mutable/MutableBoolean.java
index c0d3f5043..15ebba895 100644
--- a/src/main/java/org/apache/commons/lang3/mutable/MutableBoolean.java
+++ b/src/main/java/org/apache/commons/lang3/mutable/MutableBoolean.java
@@ -21,6 +21,8 @@
/**
* A mutable boolean
wrapper.
+ *
+ * Note that as MutableBoolean does not extend Boolean, it is not treated by String.format as a Boolean parameter.
*
* @see Boolean
* @since 2.2
diff --git a/src/main/java/org/apache/commons/lang3/mutable/MutableByte.java b/src/main/java/org/apache/commons/lang3/mutable/MutableByte.java
index 56a646ef1..37064d81e 100644
--- a/src/main/java/org/apache/commons/lang3/mutable/MutableByte.java
+++ b/src/main/java/org/apache/commons/lang3/mutable/MutableByte.java
@@ -18,6 +18,8 @@
/**
* A mutable byte
wrapper.
+ *
+ * Note that as MutableByte does not extend Byte, it is not treated by String.format as a Byte parameter.
*
* @see Byte
* @since 2.1
diff --git a/src/main/java/org/apache/commons/lang3/mutable/MutableDouble.java b/src/main/java/org/apache/commons/lang3/mutable/MutableDouble.java
index e222d7129..d0a2124ff 100644
--- a/src/main/java/org/apache/commons/lang3/mutable/MutableDouble.java
+++ b/src/main/java/org/apache/commons/lang3/mutable/MutableDouble.java
@@ -18,6 +18,8 @@
/**
* A mutable double
wrapper.
+ *
+ * Note that as MutableDouble does not extend Double, it is not treated by String.format as a Double parameter.
*
* @see Double
* @since 2.1
diff --git a/src/main/java/org/apache/commons/lang3/mutable/MutableFloat.java b/src/main/java/org/apache/commons/lang3/mutable/MutableFloat.java
index 13f4e1907..4a0512c67 100644
--- a/src/main/java/org/apache/commons/lang3/mutable/MutableFloat.java
+++ b/src/main/java/org/apache/commons/lang3/mutable/MutableFloat.java
@@ -18,6 +18,8 @@
/**
* A mutable float
wrapper.
+ *
+ * Note that as MutableFloat does not extend Float, it is not treated by String.format as a Float parameter.
*
* @see Float
* @since 2.1
diff --git a/src/main/java/org/apache/commons/lang3/mutable/MutableInt.java b/src/main/java/org/apache/commons/lang3/mutable/MutableInt.java
index e8c66bf3d..c8e396755 100644
--- a/src/main/java/org/apache/commons/lang3/mutable/MutableInt.java
+++ b/src/main/java/org/apache/commons/lang3/mutable/MutableInt.java
@@ -18,6 +18,8 @@
/**
* A mutable int
wrapper.
+ *
+ * Note that as MutableInt does not extend Integer, it is not treated by String.format as an Integer parameter.
*
* @see Integer
* @since 2.1
diff --git a/src/main/java/org/apache/commons/lang3/mutable/MutableLong.java b/src/main/java/org/apache/commons/lang3/mutable/MutableLong.java
index 59cf8103a..275450d61 100644
--- a/src/main/java/org/apache/commons/lang3/mutable/MutableLong.java
+++ b/src/main/java/org/apache/commons/lang3/mutable/MutableLong.java
@@ -18,6 +18,8 @@
/**
* A mutable long
wrapper.
+ *
+ * Note that as MutableLong does not extend Long, it is not treated by String.format as a Long parameter.
*
* @see Long
* @since 2.1
diff --git a/src/main/java/org/apache/commons/lang3/mutable/MutableShort.java b/src/main/java/org/apache/commons/lang3/mutable/MutableShort.java
index 7ce78fc9b..315e07d3b 100644
--- a/src/main/java/org/apache/commons/lang3/mutable/MutableShort.java
+++ b/src/main/java/org/apache/commons/lang3/mutable/MutableShort.java
@@ -18,6 +18,8 @@
/**
* A mutable short
wrapper.
+ *
+ * Note that as MutableShort does not extend Short, it is not treated by String.format as a Short parameter. * * @see Short * @since 2.1