1 files changed, 1 insertions, 1 deletions
diff --git a/src/nix/upgrade-nix.cc b/src/nix/upgrade-nix.cc
index 35c44a70c..6c9e37d04 100644
--- a/src/nix/upgrade-nix.cc
+++ b/src/nix/upgrade-nix.cc
@@ -106,7 +106,7 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
     {
         Path where;
 
-        for (auto & dir : tokenizeString<Strings>(getEnv("PATH"), ":"))
+        for (auto & dir : tokenizeString<Strings>(getEnv("PATH").value_or(""), ":"))
             if (pathExists(dir + "/nix-env")) {
                 where = dir;
                 break;