diff --git a/python/mozbuild/mozbuild/virtualenv.py b/python/mozbuild/mozbuild/virtualenv.py
index 0cc411e7dc63..3c563db6babd 100644
--- a/python/mozbuild/mozbuild/virtualenv.py
+++ b/python/mozbuild/mozbuild/virtualenv.py
@@ -222,6 +222,7 @@ class VirtualenvManager(object):
         called out to), the path to create the virtualenv in, and a handle to
         write output to.
         """
+        existed = os.path.exists(self.virtualenv_root)
 
         args = [python, self.virtualenv_script_path,
                 # Without this, virtualenv.py may attempt to contact the outside
@@ -233,6 +234,11 @@ class VirtualenvManager(object):
 
         result = self._log_process_output(args)
 
+        if result and existed:
+            # Try again after removing the previous env, see bug 1628644.
+            shutil.rmtree(self.virtualenv_root)
+            result = self._log_process_output(args)
+
         if result:
             raise Exception(
                 'Failed to create virtualenv: %s (virtualenv.py retcode: %s)' % (