diff --git a/bolt/test/lit.cfg.py b/bolt/test/lit.cfg.py
--- a/bolt/test/lit.cfg.py
+++ b/bolt/test/lit.cfg.py
@@ -110,4 +110,4 @@
         ('--targets-built', calculate_arch_features)
      ])
 
-config.targets = frozenset(config.targets_to_build.split())
+config.targets = frozenset(config.targets_to_build.split(';'))