diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index 143d3c2087b2dcea3176a6ec380c368cb713bc6d..78016f6cfd90e9517bc21990d9c94602bc10271f 100755
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -145,11 +145,11 @@ class Instrument:
             modulation_freqs: dictionary of modulation frequencies [Hz], or 'default'
             tdir_modulations: dictionary of callable generators of TDIR assistance modulations
                 that take an array of TPS times as argument, or None
-            clock_asds: dictionary of clock noise amplitude spectral densities
+            clock_asds: dictionary of clock noise amplitude spectral densities [/sqrt(Hz)]
             clock_offsets: dictionary of clock offsets from TPS [s]
-            clock_freqoffsets: dictionary of clock frequency offsets [s^-1], or 'default'
-            clock_freqlindrifts: dictionary of clock frequency linear drifts [s^-2], or 'default'
-            clock_freqquaddrifts: dictionary of clock frequency quadratic drifts [s^-3], or 'default'
+            clock_freqoffsets: dictionary of clock frequency offsets [s/s], or 'default'
+            clock_freqlindrifts: dictionary of clock frequency linear drifts [s/s^2], or 'default'
+            clock_freqquaddrifts: dictionary of clock frequency quadratic drifts [s/s^3], or 'default'
             clockinv_tolerance: convergence tolerance for clock noise inversion [s]
             clockinv_maxiter: maximum number of iterations for clock noise inversion
             backlink_asds: dictionary of amplitude spectral densities for backlink noise [m/sqrt(Hz)]