diff --git a/src/libutil/canon-path.cc b/src/libutil/canon-path.cc
index 07a3a6193..3b4777ef7 100644
--- a/src/libutil/canon-path.cc
+++ b/src/libutil/canon-path.cc
@@ -5,7 +5,7 @@
 
 namespace nix {
 
-CanonPath CanonPath::root = CanonPath("/");
+const CanonPath CanonPath::root = CanonPath("/");
 
 static std::string absPathPure(std::string_view path)
 {
diff --git a/src/libutil/include/nix/util/canon-path.hh b/src/libutil/include/nix/util/canon-path.hh
index dd07929b4..a9c173d71 100644
--- a/src/libutil/include/nix/util/canon-path.hh
+++ b/src/libutil/include/nix/util/canon-path.hh
@@ -69,7 +69,7 @@ public:
      */
     CanonPath(const std::vector<std::string> & elems);
 
-    static CanonPath root;
+    static const CanonPath root;
 
     /**
      * If `raw` starts with a slash, return