diff --git a/docs/_extensions/michelsonlexer.py b/docs/_extensions/michelsonlexer.py
index dc317908b22bfcb2b5a0e135800c27aa74d1de95..61f137a391f0eafdc13d62db80d82b0e769957a9 100644
--- a/docs/_extensions/michelsonlexer.py
+++ b/docs/_extensions/michelsonlexer.py
@@ -40,5 +40,5 @@ class MichelsonLexer(RegexLexer):
 
 
 def setup(sphinx):
-    sphinx.add_lexer("michelson", MichelsonLexer())
+    sphinx.add_lexer("michelson", MichelsonLexer)
     
diff --git a/docs/poetry.lock b/docs/poetry.lock
index b72501ac90f599aeace85c91939ba046dd7cadef..10d0e2987241f1b14a0b8e58cface042a6e35800 100644
--- a/docs/poetry.lock
+++ b/docs/poetry.lock
@@ -208,7 +208,7 @@ test = ["pytest", "pytest-cov", "html5lib", "cython", "typed-ast"]
 
 [[package]]
 name = "sphinx-rtd-theme"
-version = "0.4.3"
+version = "0.5.1"
 description = "Read the Docs theme for Sphinx"
 category = "main"
 optional = false
@@ -217,6 +217,9 @@ python-versions = "*"
 [package.dependencies]
 sphinx = "*"
 
+[package.extras]
+dev = ["transifex-client", "sphinxcontrib-httpdomain", "bump2version"]
+
 [[package]]
 name = "sphinxcontrib-applehelp"
 version = "1.0.2"
@@ -304,7 +307,7 @@ socks = ["PySocks (>=1.5.6,!=1.5.7,<2.0)"]
 [metadata]
 lock-version = "1.1"
 python-versions = "~3.9"
-content-hash = "8100b659869de68430f6e04b03d3a5016d5bf7d616cef4f0a86efbb9aa5c0e6c"
+content-hash = "ba85037512be7d45c3304f810c9e5512731e6b6f22c2e10d19c56f3fe7bd2ab4"
 
 [metadata.files]
 alabaster = [
@@ -416,8 +419,8 @@ sphinx = [
     {file = "Sphinx-4.1.0.tar.gz", hash = "sha256:4219f14258ca5612a0c85ed9b7222d54da69724d7e9dd92d1819ad1bf65e1ad2"},
 ]
 sphinx-rtd-theme = [
-    {file = "sphinx_rtd_theme-0.4.3-py2.py3-none-any.whl", hash = "sha256:00cf895504a7895ee433807c62094cf1e95f065843bf3acd17037c3e9a2becd4"},
-    {file = "sphinx_rtd_theme-0.4.3.tar.gz", hash = "sha256:728607e34d60456d736cc7991fd236afb828b21b82f956c5ea75f94c8414040a"},
+    {file = "sphinx_rtd_theme-0.5.1-py2.py3-none-any.whl", hash = "sha256:fa6bebd5ab9a73da8e102509a86f3fcc36dec04a0b52ea80e5a033b2aba00113"},
+    {file = "sphinx_rtd_theme-0.5.1.tar.gz", hash = "sha256:eda689eda0c7301a80cf122dad28b1861e5605cbf455558f3775e1e8200e83a5"},
 ]
 sphinxcontrib-applehelp = [
     {file = "sphinxcontrib-applehelp-1.0.2.tar.gz", hash = "sha256:a072735ec80e7675e3f432fcae8610ecf509c5f1869d17e2eecff44389cdbc58"},
diff --git a/docs/pyproject.toml b/docs/pyproject.toml
index e70aaf5404465df4c0c52e530ce9fc49f81bbfa9..496f4370449435a142ca8c9fe5a7c63c28fae016 100644
--- a/docs/pyproject.toml
+++ b/docs/pyproject.toml
@@ -13,5 +13,5 @@ keywords = ["tezos"]
 [tool.poetry.dependencies]
 python = "~3.9"
 sphinx = "*"
-sphinx-rtd-theme = "0.4.3"
+sphinx-rtd-theme = "0.5.1"
 recommonmark = "*"