diff --git a/third_party/nix/src/libstore/worker-protocol.hh b/third_party/nix/src/libstore/worker-protocol.hh
index 970d494ac..c53d079a0 100644
--- a/third_party/nix/src/libstore/worker-protocol.hh
+++ b/third_party/nix/src/libstore/worker-protocol.hh
@@ -30,8 +30,8 @@ typedef enum {
   wopQuerySubstitutablePathInfo = 21,
   wopQueryDerivationOutputs = 22,
   wopQueryAllValidPaths = 23,
-  wopQueryFailedPaths = 24,
-  wopClearFailedPaths = 25,
+  wopQueryFailedPaths = 24, // obsolete
+  wopClearFailedPaths = 25, // obsolete
   wopQueryPathInfo = 26,
   wopImportPaths = 27,  // obsolete
   wopQueryDerivationOutputNames = 28,