diff --git a/unittests/Lex/LexerTest.cpp b/unittests/Lex/LexerTest.cpp
index a708de8a5a87899d4cd7605e4ed07e34f0175c5b..4bb355393f70ce1279d9e4492ff4b1b51da761b2 100644
--- a/unittests/Lex/LexerTest.cpp
+++ b/unittests/Lex/LexerTest.cpp
@@ -383,7 +383,7 @@ TEST_F(LexerTest, DontOverallocateStringifyArgs) {
   MacroInfo *MI = PP->AllocateMacroInfo({});
   MI->setIsFunctionLike();
   MI->setArgumentList(ArgList, Allocator);
-  EXPECT_EQ(3, MI->getNumArgs());
+  EXPECT_EQ(3u, MI->getNumArgs());
   EXPECT_TRUE(MI->isFunctionLike());
 
   Token Eof;