diff --git a/doc/manual/src/release-notes/rl-next.md b/doc/manual/src/release-notes/rl-next.md
index ac662c132..2a67a39b1 100644
--- a/doc/manual/src/release-notes/rl-next.md
+++ b/doc/manual/src/release-notes/rl-next.md
@@ -2,3 +2,5 @@
 
 * The TOML parser used by `builtins.fromTOML` has been replaced by [a
   more compliant one](https://github.com/ToruNiina/toml11).
+* Added `:st`/`:show-trace` commands to nix repl, which are used to
+  set or toggle display of error traces.
diff --git a/src/nix/repl.cc b/src/nix/repl.cc
index 39a5a31de..a62ad66c2 100644
--- a/src/nix/repl.cc
+++ b/src/nix/repl.cc
@@ -430,7 +430,8 @@ bool NixRepl::processLine(string line)
              << "  :t <expr>     Describe result of evaluation\n"
              << "  :u <expr>     Build derivation, then start nix-shell\n"
              << "  :doc <expr>   Show documentation of a builtin function\n"
-             << "  :log <expr>   Show logs for a derivation\n";
+             << "  :log <expr>   Show logs for a derivation\n"
+             << "  :st [bool]    Enable, disable or toggle showing traces for errors\n";
     }
 
     else if (command == ":a" || command == ":add") {
@@ -572,6 +573,18 @@ bool NixRepl::processLine(string line)
             throw Error("value does not have documentation");
     }
 
+    else if (command == ":st" || command == ":show-trace") {
+        if (arg == "false" || (arg == "" && loggerSettings.showTrace)) {
+            std::cout << "not showing error traces\n";
+            loggerSettings.showTrace = false;
+        } else if (arg == "true" || (arg == "" && !loggerSettings.showTrace)) {
+            std::cout << "showing error traces\n";
+            loggerSettings.showTrace = true;
+        } else {
+            throw Error("unexpected argument '%s' to %s", arg, command);
+        };
+    }
+
     else if (command != "")
         throw Error("unknown command '%1%'", command);