diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index 85d3c077ba5e623725bc0d7419b9cf5742a6131d..90a4867163dfb9e1401aad2bc8f1b6d759c08784 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -193,9 +193,6 @@ LegacyArgs::LegacyArgs(const std::string & programName,
     mkFlag(0, "readonly-mode", "do not write to the Nix store",
         &settings.readOnlyMode);
 
-    mkFlag(0, "show-trace", "show Nix expression stack trace in evaluation errors",
-        &settings.showTrace);
-
     mkFlag(0, "no-gc-warning", "disable warning about not using '--add-root'",
         &gcWarning, false);
 
diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
index 81bb24a4eb38cc59918d1d750a7c8909e4930804..1e50e2d13e93486d141408eff3e1ac8fb62aa1d0 100644
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@@ -211,7 +211,8 @@ public:
     bool lockCPU;
 
     /* Whether to show a stack trace if Nix evaluation fails. */
-    bool showTrace = false;
+    Setting<bool> showTrace{this, false, "show-trace",
+        "Whether to show a stack trace on evaluation errors."};
 
     Setting<bool> enableNativeCode{this, false, "allow-unsafe-native-code-during-evaluation",
         "Whether builtin functions that allow executing native code should be enabled."};