diff --git a/doc/requirements.txt b/doc/requirements.txt
index 12cd19c1e..90449cd02 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,8 +1,8 @@
-sphinx==4.3.0
+sphinx == 4.3.0
 sphinx_rtd_theme
-sphinxcontrib-applehelp==1.0.4
-sphinxcontrib-devhelp==1.0.2
-sphinxcontrib-htmlhelp==2.0.1
-sphinxcontrib-qthelp==1.0.3
-sphinxcontrib-serializinghtml==1.1.5
+sphinxcontrib-applehelp >= 1.0.2, <= 1.0.4
+sphinxcontrib-devhelp == 1.0.2
+sphinxcontrib-htmlhelp >= 2.0.0, <= 2.0.1
+sphinxcontrib-qthelp == 1.0.3
+sphinxcontrib-serializinghtml == 1.1.5
 sphinx-autodoc-typehints