diff --git a/test/lit.cfg b/test/lit.cfg
index 929871a1d22..e65b8bec9e4 100644
--- a/test/lit.cfg
+++ b/test/lit.cfg
@@ -128,6 +128,11 @@ excludes = []
 # Provide target_triple for use in XFAIL and XTARGET.
 config.target_triple = site_exp['target_triplet']
 
+# When running under valgrind, we mangle '-vg' onto the end of the triple so we
+# can check it with XFAIL and XTARGET.
+if lit.useValgrind:
+    config.target_triple += '-vg'
+
 # Provide llvm_supports_target for use in local configs.
 targets = set(site_exp["TARGETS_TO_BUILD"].split())
 def llvm_supports_target(name):