diff --git a/etc/ci/clean_build_artifacts.sh b/etc/ci/clean_build_artifacts.sh
index cacaf96caae2..f6206485ca45 100755
--- a/etc/ci/clean_build_artifacts.sh
+++ b/etc/ci/clean_build_artifacts.sh
@@ -9,4 +9,4 @@ set -o nounset
 set -o pipefail
 
 rm -rf target/
-rm -rf python/_virtualenv/
+rm -rf python/_virtualenv*/
diff --git a/python/mach_bootstrap.py b/python/mach_bootstrap.py
index 2c83c6492e71..80b71a2bfeb2 100644
--- a/python/mach_bootstrap.py
+++ b/python/mach_bootstrap.py
@@ -145,7 +145,7 @@ def wptserve_path(is_firefox, topdir, *paths):
 
 
 def _activate_virtualenv(topdir, is_firefox):
-    virtualenv_path = os.path.join(topdir, "python", "_virtualenv")
+    virtualenv_path = os.path.join(topdir, "python", "_virtualenv%d.%d" % (sys.version_info[0], sys.version_info[1]))
     check_exec_path = lambda path: path.startswith(virtualenv_path)
     python = sys.executable   # If there was no python, mach wouldn't have run at all!
     if not python: