Scrollbar of code block not shown when embeded in admonition block

Hi,
In HTML ouput, using source code highlighter highlightjs, this kind of code block:

.example.properties
[source,properties,options=nowrap]
a_property_with_some_very_long_line_content=abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef

is nicely displayed with a scroll bar:



But when embeded within an admonition block:

[NOTE]
--
.example.properties
[source,properties,options=nowrap]
a_property_with_some_very_long_line_content=abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef|abcdef
--

it doesn't work:



Any idea?
thanks