HTTP "out" binding does not work with DecimalType

My .items file has the following record:

Number Ugenerated_0 "Генерация [%.0f В]" <inverter> (MAPGEN1)
{ http="<[] >[*:GET:$.0f]"}

which I want to use both to read and update the value via HTTP Binding

The “in” part works OK, but the "out@ generates error
java.util.IllegalFormatConversionException: f != org.openhab.core.library.types.DecimalType

If I understand it right - there is a mismatch between %.0f formatter specification and Openhab Decimaltype.
The actial value of Ugenarated_0 = 220

I found a workaround via .rules, but looking for direct solution of this problem