diff --git a/doc/conf.py b/doc/conf.py
index a5e0f81f..30a47733 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -40,6 +40,7 @@
     "sphinx.ext.autodoc",
     "sphinx.ext.autosummary",
     "sphinx.ext.doctest",
+    "sphinx.ext.imgconverter",
     "sphinx.ext.intersphinx",
     "sphinx.ext.linkcode",
     "sphinx.ext.mathjax",
@@ -76,7 +77,6 @@
     "pyebsdindex": ("https://pyebsdindex.readthedocs.io/en/stable", None),
     "pyopencl": ("https://documen.tician.de/pyopencl/", None),
     "pytest": ("https://docs.pytest.org/en/stable", None),
-    #    "pythreejs": ("https://pythreejs.readthedocs.io/en/stable", None),
     "python": ("https://docs.python.org/3", None),
     "pyvista": ("https://docs.pyvista.org", None),
     "pyxem": ("https://pyxem.readthedocs.io/en/latest", None),
@@ -186,7 +186,10 @@
 latex_elements = {
     # pdflatex doesn't like some Unicode characters, so a replacement
     # for one of them is made here
-    "preamble": r"\DeclareUnicodeCharacter{2588}{-}"
+    "preamble": r"""
+    \DeclareUnicodeCharacter{2588}{-}
+    \DeclareUnicodeCharacter{03BC}{u}
+    """
 }
 
 
diff --git a/readthedocs.yaml b/readthedocs.yaml
index 11ddfebf..092a56c4 100644
--- a/readthedocs.yaml
+++ b/readthedocs.yaml
@@ -16,16 +16,17 @@ build:
     python: "3.10"
     nodejs: "19"
   # See https://docs.pyvista.org/user-guide/jupyter/panel.html#configuration-considerations.
-  # These packages are needed by PyVista/panel to render 3D plots from
-  # RTD's server.
+  # Some of these packages are needed by PyVista/panel to render 3D
+  # plots from RTD's server.
   apt_packages:
+    - imagemagick
     - libgl1-mesa-dev
     - xvfb
 
 # Build doc in all formats (HTML, PDF and ePub)
 formats:
-  - htmlzip
   - pdf
+#  - htmlzip
 
 # Python environment for building the docs
 python: