diff --git a/cmake/Modules/Documentation.cmake b/cmake/Modules/Documentation.cmake
index 1381e4fef0..282253eede 100644
--- a/cmake/Modules/Documentation.cmake
+++ b/cmake/Modules/Documentation.cmake
@@ -29,8 +29,8 @@ if(BUILD_DOC)
     OUTPUT requirements.txt
     DEPENDS docenv
     COMMAND ${CMAKE_COMMAND} -E copy ${LAMMPS_DOC_DIR}/utils/requirements.txt requirements.txt
-    COMMAND ${DOCENV_BINARY_DIR}/pip install -r requirements.txt --upgrade
     COMMAND ${DOCENV_BINARY_DIR}/pip install --upgrade ${LAMMPS_DOC_DIR}/utils/converters
+    COMMAND ${DOCENV_BINARY_DIR}/pip install --use-feature=2020-resolver -r requirements.txt --upgrade
   )
 
   # download mathjax distribution and unpack to folder "mathjax"
diff --git a/doc/Makefile b/doc/Makefile
index bf70e5d602..293884b17f 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -194,7 +194,7 @@ $(VENV):
 		$(VIRTUALENV) -p $(PYTHON) $(VENV); \
 		. $(VENV)/bin/activate; \
 		pip install --upgrade pip; \
-		pip install -r requirements.txt; \
+		pip install --use-feature=2020-resolver -r requirements.txt; \
 		deactivate;\
 	)