BODS Issue with NUMC - DECIMAL column

We observed one scenario in BODS while loading data from SAP ECC to HANA target which is as follows:

Source column in ECC is defined as NUMC(X,Y) say X and Y are some value like NUMC(4,0)

Target column in HANA is defined as DECIMAL(4,0) for the above

Scenario:

If the source column value is NULL , then this is getting loaded as ‘0’ in target via BODS (there is no default value specified at column level in )

target table)

I want to understand that why BODS is behaving in such way for this column datatype and is there any way through which we can avoid such scenario in BODS.