diff --git a/llvm/utils/gn/secondary/llvm/lib/SandboxIR/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/SandboxIR/BUILD.gn
index c6fbddb4bf13ab..abf09e9d84045e 100644
--- a/llvm/utils/gn/secondary/llvm/lib/SandboxIR/BUILD.gn
+++ b/llvm/utils/gn/secondary/llvm/lib/SandboxIR/BUILD.gn
@@ -6,6 +6,7 @@ static_library("SandboxIR") {
     "//llvm/lib/Support",
   ]
   sources = [
+    "Argument.cpp",
     "Context.cpp",
     "Module.cpp",
     "Pass.cpp",