diff --git a/lib/Support/CommandLine.cpp b/lib/Support/CommandLine.cpp
index 2b4fba8062c..7e744993a7c 100644
--- a/lib/Support/CommandLine.cpp
+++ b/lib/Support/CommandLine.cpp
@@ -185,7 +185,8 @@ static Option *LookupOption(StringRef &Arg, StringRef &Value,
/// (after an equal sign) return that as well. This assumes that leading dashes
/// have already been stripped.
static Option *LookupNearestOption(StringRef Arg,
- const StringMap