diff --git a/src/macro.c b/src/macro.c
index 41260c6e..56288401 100644
--- a/src/macro.c
+++ b/src/macro.c
@@ -24,9 +24,15 @@ new_uniq_sym(pic_state *pic, pic_sym base)
 
   str = (char *)pic_alloc(pic, strlen(pic_symbol_name(pic, base)) + (int)log10(s) + 3);
   sprintf(str, "%s@%d", pic_symbol_name(pic, base), s);
-  uniq = pic_intern_cstr(pic, str);
 
-  pic_free(pic, str);
+  /* don't put the symbol to ic->sym_tbl to keep it uninterned */
+  if (pic->slen >= pic->scapa) {
+    pic->scapa *= 2;
+    pic->sym_pool = pic_realloc(pic, pic->sym_pool, sizeof(const char *) * pic->scapa);
+  }
+  uniq = pic->slen++;
+  pic->sym_pool[uniq] = str;
+
   return uniq;
 }