diff --git a/doc/src/compute_viscosity_cos.rst b/doc/src/compute_viscosity_cos.rst
index d08217a590..2f7a09924c 100644
--- a/doc/src/compute_viscosity_cos.rst
+++ b/doc/src/compute_viscosity_cos.rst
@@ -21,12 +21,13 @@ Examples
 
 .. code-block:: LAMMPS
 
+   units    real
    compute  cos all viscosity/cos
    variable V equal c_cos[7]
-   variable A equal 0.02E-5
+   variable A equal 0.02E-5  # A/fs^2
    variable density equal density
    variable lz equal lz
-   variable reciprocalViscosity equal v_V/${A}/v_density*39.4784/v_lz/v_lz*100
+   variable reciprocalViscosity equal v_V/${A}/v_density*39.4784/v_lz/v_lz*100  # 1/(Pa*s)
 
 Description
 """""""""""
diff --git a/doc/src/fix_accelerate_cos.rst b/doc/src/fix_accelerate_cos.rst
index 46e08e68b4..904e853ad8 100644
--- a/doc/src/fix_accelerate_cos.rst
+++ b/doc/src/fix_accelerate_cos.rst
@@ -13,7 +13,7 @@ Syntax
 
 * ID, group-ID are documented in :doc:`fix <fix>` command
 * accelerate/cos = style name of this fix command
-* value = amplitude of acceleration (in unit of force/mass)
+* value = amplitude of acceleration (in unit of velocity/time)
 
 
 Examples