Locating the node by value containing whitespaces using XPath

I need to locate the node within an xml file by its value using XPath. The problem araises when the node to find contains value with whitespaces inside. F.e.:

<Root>
  <Child>value</Child>
  <Child>value with spaces</Child>
</Root>

I can not construct the XPath locating the second Child node.

Simple XPath /Root/Child perfectly works for both children, but /Root[Child=value with spaces] returns an empty collection.

I have already tried masking spaces with %20, & #20;, & nbsp; and using quotes and double quotes.

Still no luck.

Does anybody have an idea?