diff --git a/string.c b/string.c
index 3a7113dcc0..394fa8d332 100644
--- a/string.c
+++ b/string.c
@@ -10036,6 +10036,8 @@ Init_String(void)
 #define rb_intern(str) rb_intern_const(str)
 
     rb_cString  = rb_define_class("String", rb_cObject);
+    assert(rb_vm_fstring_table());
+    st_foreach(rb_vm_fstring_table(), fstring_set_class_i, rb_cString);
     rb_include_module(rb_cString, rb_mComparable);
     rb_define_alloc_func(rb_cString, empty_str_alloc);
     rb_define_singleton_method(rb_cString, "try_convert", rb_str_s_try_convert, 1);
@@ -10215,7 +10217,4 @@ Init_String(void)
     rb_define_method(rb_cSymbol, "swapcase", sym_swapcase, -1);
 
     rb_define_method(rb_cSymbol, "encoding", sym_encoding, 0);
-
-    assert(rb_vm_fstring_table());
-    st_foreach(rb_vm_fstring_table(), fstring_set_class_i, rb_cString);
 }
diff --git a/symbol.c b/symbol.c
index facdb3ce24..f4516ebbe4 100644
--- a/symbol.c
+++ b/symbol.c
@@ -744,15 +744,7 @@ rb_sym2str(VALUE sym)
 VALUE
 rb_id2str(ID id)
 {
-    VALUE str;
-
-    if ((str = lookup_id_str(id)) != 0) {
-        if (RBASIC(str)->klass == 0)
-            RBASIC_SET_CLASS_RAW(str, rb_cString);
-	return str;
-    }
-
-    return 0;
+    return lookup_id_str(id);
 }
 
 const char *