diff --git a/tools/llvm-xray/xray-extract.cc b/tools/llvm-xray/xray-extract.cc
index 34bda48c751e..c2c51062075e 100644
--- a/tools/llvm-xray/xray-extract.cc
+++ b/tools/llvm-xray/xray-extract.cc
@@ -58,6 +58,9 @@ struct YAMLXRaySledEntry {
   bool AlwaysInstrument;
 };
 
+namespace llvm {
+namespace yaml {
+
 template <> struct ScalarEnumerationTraits<SledEntry::FunctionKinds> {
   static void enumeration(IO &IO, SledEntry::FunctionKinds &Kind) {
     IO.enumCase(Kind, "function-enter", SledEntry::FunctionKinds::ENTRY);
@@ -78,6 +81,9 @@ template <> struct MappingTraits<YAMLXRaySledEntry> {
   static constexpr bool flow = true;
 };
 
+}
+}
+
 LLVM_YAML_IS_SEQUENCE_VECTOR(YAMLXRaySledEntry)
 
 namespace {