error parsing -s (mono-exonic coverage)

[noncodo]

Trying to change the -s parameter throws Error: invalid -s value, must be >=0.001)

Full command:
stringtie -p 120 -E 15 -m 50 -s 2.00 -t -R -L -A geneAbundance.txt -G gencode.vM37.chr_patch_hapl_scaff.annotation.gtf -o output.gtf files.bam