diff --git a/tests/letstest/scripts/test_sdists.sh b/tests/letstest/scripts/test_sdists.sh
index 53a783bb6..55ff85d5a 100755
--- a/tests/letstest/scripts/test_sdists.sh
+++ b/tests/letstest/scripts/test_sdists.sh
@@ -6,7 +6,15 @@ BOOTSTRAP_SCRIPT="tests/letstest/scripts/bootstrap_os_packages.sh"
 VENV_PATH=venv3
 
 # bootstrap and setup venv
-sudo $BOOTSTRAP_SCRIPT . "CERTBOT_PIP_NO_BINARY=:all: $VENV_SCRIPT --requirement letsencrypt-auto-source/pieces/dependency-requirements.txt"
+sudo $BOOTSTRAP_SCRIPT
+CERTBOT_PIP_NO_BINARY=:all: tools/venv3.py --requirement letsencrypt-auto-source/pieces/dependency-requirements.txt
+
+if command -v python && [ $(python -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//') -eq 26 ]; then
+  # RHEL/CentOS 6 will need a special treatment, so we need to detect that environment
+  # Enable the SCL Python 3.6 installed by letsencrypt-auto bootstrap
+  PATH="/opt/rh/rh-python36/root/usr/bin:$PATH"
+fi
+
 . "$VENV_PATH/bin/activate"
 # pytest is needed to run tests on some of our packages so we install a pinned version here.
 tools/pip_install.py pytest
diff --git a/tests/letstest/scripts/test_tests.sh b/tests/letstest/scripts/test_tests.sh
index 3be9e8ace..f62584709 100755
--- a/tests/letstest/scripts/test_tests.sh
+++ b/tests/letstest/scripts/test_tests.sh
@@ -13,9 +13,16 @@ VENV_NAME=venv3
 BOOTSTRAP_SCRIPT="$REPO_ROOT/tests/letstest/scripts/bootstrap_os_packages.sh"
 VENV_SCRIPT="tools/venv3.py"
 
-sudo $BOOTSTRAP_SCRIPT $REPO_ROOT $VENV_SCRIPT
+sudo $BOOTSTRAP_SCRIPT
+
+if command -v python && [ $(python -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//') -eq 26 ]; then
+  # RHEL/CentOS 6 will need a special treatment, so we need to detect that environment
+  # Enable the SCL Python 3.6 installed by letsencrypt-auto bootstrap
+  PATH="/opt/rh/rh-python36/root/usr/bin:$PATH"
+fi
 
 cd $REPO_ROOT
+$VENV_SCRIPT
 . $VENV_NAME/bin/activate
 "$PIP_INSTALL" pytest