diff --git a/watchman/PDU.cpp b/watchman/PDU.cpp
index 8d47556d553d..3166069f753b 100644
--- a/watchman/PDU.cpp
+++ b/watchman/PDU.cpp
@@ -581,18 +581,18 @@ ResultErrno<folly::Unit> PduBuffer::jsonEncodeToStream(
 }
 
 ResultErrno<folly::Unit> PduBuffer::pduEncodeToStream(
-    PduFormat format,
+    PduFormat format_2,
     const json_ref& json,
     watchman_stream* stm) {
-  switch (format.type) {
+  switch (format_2.type) {
     case is_json_compact:
       return jsonEncodeToStream(json, stm, JSON_COMPACT);
     case is_json_pretty:
       return jsonEncodeToStream(json, stm, JSON_INDENT(4));
     case is_bser:
-      return bserEncodeToStream(1, format.capabilities, json, stm);
+      return bserEncodeToStream(1, format_2.capabilities, json, stm);
     case is_bser_v2:
-      return bserEncodeToStream(2, format.capabilities, json, stm);
+      return bserEncodeToStream(2, format_2.capabilities, json, stm);
     case need_data:
     default:
       return EINVAL;