diff --git a/pyccl/power.py b/pyccl/power.py
index 61d152ac7..f4235fc9c 100644
--- a/pyccl/power.py
+++ b/pyccl/power.py
@@ -104,7 +104,7 @@ def sigmaR(cosmo, R, a=1, *, p_of_k_a=DEFAULT_POWER_SPECTRUM):
         \\sigma_R^2(z)=\\frac{1}{2\\pi^2}\\int dk\\,k^2\\,P(k,z)\\,
         |W(kR)|^2,
 
-    with :math:`W(x)=(3\\sin(x)-x\\cos(x))/x^3`.
+    with :math:`W(x)=3(\\sin(x)-x\\cos(x))/x^3`.
 
     Args:
         cosmo (:class:`~pyccl.cosmology.Cosmology`): Cosmological parameters.
@@ -134,7 +134,7 @@ def sigmaV(cosmo, R, a=1, *, p_of_k_a=DEFAULT_POWER_SPECTRUM):
     .. math::
         \\sigma_V^2(z)=\\frac{1}{6\\pi^2}\\int dk\\,P(k,z)\\,|W(kR)|^2,
 
-    with :math:`W(x)=(3\\sin(x)-x\\cos(x))/x^3`.
+    with :math:`W(x)=3(\\sin(x)-x\\cos(x))/x^3`.
 
     Args:
         cosmo (:class:`~pyccl.cosmology.Cosmology`): Cosmological parameters.
diff --git a/readthedocs/requirements.txt b/readthedocs/requirements.txt
index 018445c16..9342a8a47 100644
--- a/readthedocs/requirements.txt
+++ b/readthedocs/requirements.txt
@@ -1,6 +1,6 @@
-sphinx==6
+sphinx
 sphinx_mdinclude
 numpy
 scipy
-docutils>=0.18
-sphinx_rtd_theme==1.2.0rc3
+docutils
+sphinx_rtd_theme