diff --git a/docs/CMakeLists.txt b/docs/CMakeLists.txt
index b17780a..c6caa21 100644
--- a/docs/CMakeLists.txt
+++ b/docs/CMakeLists.txt
@@ -16,7 +16,7 @@
 
 # suppress warnings on mismatched names in PythonModules
 set(FPHSA_NAME_MISMATCHED True)
-find_package(PythonModules COMPONENTS m2r sphinx-rtd-theme sphinxcontrib.plantuml)
+find_package(PythonModules COMPONENTS m2r2 sphinx-rtd-theme sphinxcontrib.plantuml)
 find_package(PlantUML)
 find_package(Doxygen 1.8.0)
 find_package(LATEX COMPONENTS PDFLATEX)
@@ -52,7 +52,7 @@
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/tfm_env.py.in ${SPHINX_TMP_DOC_DIR}/tfm_env.py @ONLY)
 
-if (SPHINX_FOUND AND PLANTUML_FOUND AND PY_M2R_FOUND AND PY_SPHINX-RTD-THEME_FOUND AND PY_SPHINXCONTRIB.PLANTUML)
+if (SPHINX_FOUND AND PLANTUML_FOUND AND PY_M2R2_FOUND AND PY_SPHINX-RTD-THEME_FOUND AND PY_SPHINXCONTRIB.PLANTUML)
 
     file(GLOB_RECURSE SPHINXCFG_DOC_FILES ${CMAKE_CURRENT_SOURCE_DIR}/*.rst)
 
diff --git a/docs/conf.py.in b/docs/conf.py.in
index eeff3ba..7efc1db 100644
--- a/docs/conf.py.in
+++ b/docs/conf.py.in
@@ -47,7 +47,7 @@
 # ones.
 extensions = [
     'sphinx.ext.imgmath',
-    'm2r', #Support markdown files. Needed for external code.
+    'm2r2', #Support markdown files. Needed for external code.
     'sphinx.ext.autosectionlabel', #Make sphinx generate a label for each section
     'sphinxcontrib.plantuml', #Add support for PlantUML drawings
     'sphinxcontrib.rsvgconverter', #Add support for SVG to PDF
@@ -127,7 +127,7 @@
 
 #Add custom css for HTML. Used to allow full page width rendering
 def setup(app):
-    app.add_stylesheet('css/tfm_custom.css')
+    app.add_css_file('css/tfm_custom.css')
 
 # -- Options for HTMLHelp output ---------------------------------------------
 
diff --git a/tools/requirements_docs.txt b/tools/requirements_docs.txt
index 762208e..4678dc5 100644
--- a/tools/requirements_docs.txt
+++ b/tools/requirements_docs.txt
@@ -1,10 +1,10 @@
 graphviz
-Jinja2>=2.10.3
+Jinja2>=3.0.2
 latex
-Sphinx==2.0.1
-m2r
-sphinx-rtd-theme
-sphinxcontrib-plantuml
-sphinxcontrib-svg2pdfconverter
-sphinx-tabs==1.1.13
+Sphinx==4.2.0
+m2r2
+sphinx-rtd-theme>=1.0.0
+sphinxcontrib-plantuml==0.22
+sphinxcontrib-svg2pdfconverter==1.1.1
+sphinx-tabs==3.2.0
 docutils==0.16