diff --git a/reference/pdo/pdostatement/fetchcolumn.xml b/reference/pdo/pdostatement/fetchcolumn.xml
index 0ab8ac2895..60fabe32e2 100644
--- a/reference/pdo/pdostatement/fetchcolumn.xml
+++ b/reference/pdo/pdostatement/fetchcolumn.xml
@@ -11,7 +11,7 @@
  <refsect1 role="description">
   &reftitle.description;
   <methodsynopsis>
-   <modifier>public</modifier> <type>string</type><methodname>PDOStatement::fetchColumn</methodname>
+   <modifier>public</modifier> <type>mixed</type><methodname>PDOStatement::fetchColumn</methodname>
    <methodparam choice="opt"><type>int</type><parameter>column_number</parameter><initializer>0</initializer></methodparam>
   </methodsynopsis>
 
@@ -19,6 +19,15 @@
    Returns a single column from the next row of a result set or &false; if
    there are no more rows.
   </para>
+
+  <note>
+   <para>
+    <function>PDOStatement::fetchColumn</function> should not be used to
+    retrieve boolean columns, as it is impossible to distinguish a value of
+    &false; from there being no more rows to retrieve. Use
+    <function>PDOStatement::fetch</function> instead.
+   </para>
+  </note>
  </refsect1>
 
  <refsect1 role="parameters">