diff --git a/pila.c b/pila.c
index 409112c..28c54d9 100644
--- a/pila.c
+++ b/pila.c
@@ -174,21 +174,22 @@ push_val(RpnState *st, Value val)
 	st->data_stack[st->sp++] = val;
 }
 
-Value
-top_val(RpnState *st)
+bool
+top_val(RpnState *st, Value *val)
 {
 	if (st->sp == 0) {
 		signal_error(st, "stack underflow");
-		return Nil;
+		return false;
 	}
-	return st->data_stack[st->sp - 1];
+	*val = st->data_stack[st->sp - 1];
+	return true;
 }
 
 Value
 pop_val(RpnState *st)
 {
-	Value val = top_val(st);
-	if (val.kind == VAL_NIL)
+	Value val;
+	if (!top_val(st, &val))
 		return Nil;
 	--st->sp;
 	return val;
@@ -256,7 +257,9 @@ not_nat(RpnState *st)
 void
 dup_nat(RpnState *st)
 {
-	push_val(st, top_val(st));
+	Value val;
+	top_val(st, &val);
+	push_val(st, val);
 }
 
 void
@@ -430,6 +433,14 @@ to_number_nat(RpnState *st)
 	push_val(st, BOX_INTN(n));
 }
 
+void
+parse_word_nat(RpnState *st)
+{
+	skip_whitespace(&st->rsp, st->rep);
+	Str wn = read_word_name(&st->rsp, st->rep);
+	push_val(st, BOX_STR(wn));
+}
+
 void
 add_word(RpnState *st, Word *w)
 {
@@ -623,6 +634,7 @@ main(int argc, char **argv)
 		{.name = Sl(";"), .kind = WORD_NATIVE, .nat = compile_end_nat },
 		{.name = Sl("'"), .kind = WORD_NATIVE, .nat = tick_nat },
 		{.name = Sl(">#"), .kind = WORD_NATIVE, .nat = to_number_nat },
+		{.name = Sl("parse-word"), .kind = WORD_NATIVE, .nat = parse_word_nat },
 		{.name = Sl("exec"), .kind = WORD_NATIVE, .nat = exec_nat},
 		{.name = Sl("eval"), .kind = WORD_NATIVE, .nat = eval_nat},
 		{.name = Sl("dup"), .kind = WORD_NATIVE, .nat = dup_nat },