diff --git a/src/libstore/nar-info.cc b/src/libstore/nar-info.cc
index ee2ddfd81..2b77c6ab7 100644
--- a/src/libstore/nar-info.cc
+++ b/src/libstore/nar-info.cc
@@ -4,6 +4,15 @@
 
 namespace nix {
 
+GENERATE_CMP_EXT(
+    ,
+    NarInfo,
+    me->url,
+    me->compression,
+    me->fileHash,
+    me->fileSize,
+    static_cast<const ValidPathInfo &>(*me));
+
 NarInfo::NarInfo(const Store & store, const std::string & s, const std::string & whence)
     : ValidPathInfo(StorePath(StorePath::dummy), Hash(Hash::dummy)) // FIXME: hack
 {
diff --git a/src/libstore/nar-info.hh b/src/libstore/nar-info.hh
index 5dbdafac3..1b3551106 100644
--- a/src/libstore/nar-info.hh
+++ b/src/libstore/nar-info.hh
@@ -24,6 +24,8 @@ struct NarInfo : ValidPathInfo
     NarInfo(const ValidPathInfo & info) : ValidPathInfo(info) { }
     NarInfo(const Store & store, const std::string & s, const std::string & whence);
 
+    DECLARE_CMP(NarInfo);
+
     std::string to_string(const Store & store) const;
 };