diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 2345a5e3c..9ec32a0de 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -826,7 +826,7 @@ static void prim_addErrorContext(EvalState & state, const PosIdx pos, Value * *
         auto message = state.coerceToString(pos, *args[0], context,
                 "while evaluating the error message passed to builtins.addErrorContext",
                 false, false).toOwned();
-        e.addTrace(nullptr, HintFmt(message), TraceKind::Custom);
+        e.addTrace(nullptr, HintFmt(message), TracePrint::Always);
         throw;
     }
 }
diff --git a/src/libutil/error.cc b/src/libutil/error.cc
index e9c6437cd..036e19e26 100644
--- a/src/libutil/error.cc
+++ b/src/libutil/error.cc
@@ -11,9 +11,9 @@
 
 namespace nix {
 
-void BaseError::addTrace(std::shared_ptr<Pos> && e, HintFmt hint, TraceKind kind)
+void BaseError::addTrace(std::shared_ptr<Pos> && e, HintFmt hint, TracePrint print)
 {
-    err.traces.push_front(Trace { .pos = std::move(e), .hint = hint, .kind = kind });
+    err.traces.push_front(Trace { .pos = std::move(e), .hint = hint, .print = print });
 }
 
 void throwExceptionSelfCheck(){
@@ -388,7 +388,7 @@ std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool s
                 truncate = true;
             }
 
-            if (!truncate || trace.kind == TraceKind::Custom) {
+            if (!truncate || trace.print == TracePrint::Always) {
 
                 if (tracesSeen.count(trace)) {
                     skippedTraces.push_back(trace);
diff --git a/src/libutil/error.hh b/src/libutil/error.hh
index 6701a75b3..d23625a54 100644
--- a/src/libutil/error.hh
+++ b/src/libutil/error.hh
@@ -61,16 +61,22 @@ void printCodeLines(std::ostream & out,
     const Pos & errPos,
     const LinesOfCode & loc);
 
-enum struct TraceKind {
-    Other,
-    /** Produced by builtins.addErrorContext. Always printed. */
-    Custom,
+/**
+ * When a stack frame is printed.
+ */
+enum struct TracePrint {
+    /**
+     * The default behavior; always printed when `--show-trace` is set.
+     */
+    Default,
+    /** Always printed. Produced by `builtins.addErrorContext`. */
+    Always,
 };
 
 struct Trace {
     std::shared_ptr<Pos> pos;
     HintFmt hint;
-    TraceKind kind = TraceKind::Other;
+    TracePrint print = TracePrint::Default;
 };
 
 inline bool operator<(const Trace& lhs, const Trace& rhs);
@@ -168,7 +174,7 @@ public:
         addTrace(std::move(e), HintFmt(std::string(fs), args...));
     }
 
-    void addTrace(std::shared_ptr<Pos> && e, HintFmt hint, TraceKind kind = TraceKind::Other);
+    void addTrace(std::shared_ptr<Pos> && e, HintFmt hint, TracePrint print = TracePrint::Default);
 
     bool hasTrace() const { return !err.traces.empty(); }