  We introduce a technique to mitigate the effects of low frequency noise on
precision timing. The example of Dark Count Noise Rate (DCR) in Silicon
Photomultipliers (SiPMs) is emphasized. This technique exploits the correlation
between time shifts on the leading edge of a signal and the residual slope of
the baseline (due to noise) which remains after baseline subtraction.
  In fast timing applications (such as for Time-of-flight particle ID) the
signal arrival time is typically captured on the signal leading edge.
  The signal risetime is often fixed by the physics of the sensor and input
circuit. Then accurate pulse timing can be achieved by correcting a leading
edge threshold time (depending on a slope proportional to both the Amplitude
and the risetime) to a ``constant fraction" time.
  This compensation for time walk due to amplitude fluctuations breaks down
once we introduce interference from low frequency noise on the leading edge. In
this paper we demonstrate that an additional measurement of the slope at
threshold can be used to correct for this noise jitter.
