diff --git a/HTMLtree.c b/HTMLtree.c
index ab5c816a..06741c21 100644
--- a/HTMLtree.c
+++ b/HTMLtree.c
@@ -311,6 +311,8 @@ static const char* const htmlBooleanAttrs[] = {
  * htmlIsBooleanAttr:
  * @name:  the name of the attribute to check
  *
+ * DEPRECATED: Internal function, don't use.
+ *
  * Determine if a given attribute is a boolean attribute.
  *
  * returns: false if the attribute is not boolean, true otherwise.
diff --git a/include/libxml/HTMLtree.h b/include/libxml/HTMLtree.h
index 8e1ba90e..065254f4 100644
--- a/include/libxml/HTMLtree.h
+++ b/include/libxml/HTMLtree.h
@@ -133,6 +133,7 @@ XMLPUBFUN void
 
 #endif /* LIBXML_OUTPUT_ENABLED */
 
+XML_DEPRECATED
 XMLPUBFUN int
 		htmlIsBooleanAttr	(const xmlChar *name);
 
diff --git a/python/generator.py b/python/generator.py
index 2d329207..0d175d2d 100755
--- a/python/generator.py
+++ b/python/generator.py
@@ -295,6 +295,7 @@ deprecated_funcs = {
     'htmlHandleOmittedElem': True,
     'htmlInitAutoClose': True,
     'htmlIsAutoClosed': True,
+    'htmlIsBooleanAttr': True,
     'htmlParseCharRef': True,
     'htmlParseElement': True,
     'namePop': True,