diff --git a/.github/kokoro/steps/hostsetup.sh b/.github/kokoro/steps/hostsetup.sh
index 7f2948ed..9ce9f995 100755
--- a/.github/kokoro/steps/hostsetup.sh
+++ b/.github/kokoro/steps/hostsetup.sh
@@ -66,6 +66,7 @@ sudo apt-get install -y \
         python3 \
         python3-dev \
         python3-virtualenv \
+        python3-venv \
         python3-yaml \
         virtualenv \
 
diff --git a/Makefile b/Makefile
index efe6deef..293407a4 100644
--- a/Makefile
+++ b/Makefile
@@ -18,18 +18,13 @@ endif
 # Tools + Environment
 IN_ENV = if [ -e env/bin/activate ]; then . env/bin/activate; fi; source utils/environment.python.sh;
 env:
-	virtualenv --python=python3 env
-	# Install prjxray
-	ln -sf $(PWD)/prjxray env/lib/python3.*/site-packages/
-	$(IN_ENV) python -c "import prjxray"
-	# Install fasm from third_party
-	$(IN_ENV) pip install --upgrade -e third_party/fasm
-	# Install sdfparse form third party
-	$(IN_ENV) pip install --upgrade -e third_party/python-sdf-timing
+	python3 -mvenv env
 	# Install project dependencies
-	$(IN_ENV) pip install -r requirements.txt
+	$(IN_ENV) python -mpip install -r requirements.txt
 	# Install project's documentation dependencies
-	$(IN_ENV) pip install -r docs/requirements.txt
+	$(IN_ENV) python -mpip install -r docs/requirements.txt
+	# Check that prjxray are available
+	$(IN_ENV) python -c "import prjxray"
 	# Check fasm library was installed
 	$(IN_ENV) python -c "import fasm"
 	$(IN_ENV) python -c "import fasm.output"
diff --git a/requirements.txt b/requirements.txt
index 6fd01535..e10243ab 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,6 @@
 -e third_party/fasm
 -e third_party/python-sdf-timing
+-e .
 intervaltree
 junit-xml
 numpy
diff --git a/utils/environment.python.sh b/utils/environment.python.sh
index a4b8e382..06577010 100644
--- a/utils/environment.python.sh
+++ b/utils/environment.python.sh
@@ -1,4 +1,3 @@
-# FIXME: fasm should be installed into the running Python environment.
 # Copyright (C) 2017-2020  The Project X-Ray Authors.
 #
 # Use of this source code is governed by a ISC-style
@@ -6,7 +5,6 @@
 # https://opensource.org/licenses/ISC
 #
 # SPDX-License-Identifier: ISC
-export PYTHONPATH="${XRAY_DIR}:${XRAY_DIR}/third_party/fasm:$PYTHONPATH"
 
 # Suppress the following warnings;
 # - env/lib/python3.7/distutils/__init__.py:4: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses