Hybrid detectors and multichannel-plate (MCP) PMTs achieve a timing resolution (IRF width) of less than 20 ps FWHM when operated with the new bh SPC-150NX TCSPC modules. As a test light source, we used a Toptica FemtoFErb laser with a pulse width of 100 fs. The laser beam was directed through a package of ND filters to the photocathodes of a bh HPM-100-06 and a HPM-100-07 detector (based on Hamamatsu R10467-06 and -07 tubes) and a Hamamatsu R3809U-50 MCP PMT. In all cases, an IRF width around 20 ps FWHM and below was obtained. This is considerably shorter than previously reported for these detectors. We attribute the improvement to the superior bandwidth of the SPC-150N discriminators and the extremely low timing jitter of the timing electronics of the SPC-150NX modules.