diff --git a/llvm/lib/Support/Windows/Program.inc b/llvm/lib/Support/Windows/Program.inc
index 942dfda99c98..db20e21ee048 100644
--- a/llvm/lib/Support/Windows/Program.inc
+++ b/llvm/lib/Support/Windows/Program.inc
@@ -82,7 +82,7 @@ ErrorOr<std::string> sys::findProgramByName(StringRef Name,
   std::u16string PathStorage;
   if (!Paths.empty()) {
     PathStorage.reserve(Paths.size() * MAX_PATH);
-    for (int i = 0; i < Paths.size(); ++i) {
+    for (unsigned i = 0; i < Paths.size(); ++i) {
       if (i)
         PathStorage.push_back(';');
       StringRef P = Paths[i];