diff --git a/utils/gn/secondary/clang/unittests/Format/BUILD.gn b/utils/gn/secondary/clang/unittests/Format/BUILD.gn
index b5f50a62cc2..b5632ce40b5 100644
--- a/utils/gn/secondary/clang/unittests/Format/BUILD.gn
+++ b/utils/gn/secondary/clang/unittests/Format/BUILD.gn
@@ -17,6 +17,7 @@ unittest("FormatTests") {
     "FormatTestComments.cpp",
     "FormatTestJS.cpp",
     "FormatTestJava.cpp",
+    "FormatTestJson.cpp",
     "FormatTestObjC.cpp",
     "FormatTestProto.cpp",
     "FormatTestRawStrings.cpp",