diff --git a/llvm/test/Analysis/lit.local.cfg b/llvm/test/Analysis/lit.local.cfg
new file mode 100644
--- /dev/null
+++ b/llvm/test/Analysis/lit.local.cfg
@@ -0,0 +1,9 @@
+# -*- Python -*- vim: set ft=python ts=4 sw=4 expandtab tw=79:
+from lit.llvm.subst import ToolSubst
+
+fc = ToolSubst('FileCheck', unresolved='fatal')
+# Insert this first. Then, we'll first update the blank FileCheck command; then,
+# the default substitution of FileCheck will replace it to its full path.
+config.substitutions.insert(0, (fc.regex, 
+    'FileCheck --allow-unused-prefixes=false'))
+