diff --git a/marshal.c b/marshal.c
index 4cba05d..dfce6ee 100644
--- a/marshal.c
+++ b/marshal.c
@@ -1312,7 +1312,9 @@ r_unique(struct load_arg *arg)
 static VALUE
 r_string(struct load_arg *arg)
 {
-    return r_bytes(arg);
+    VALUE str = r_bytes(arg);
+    rb_enc_associate(str, rb_utf8_encoding());
+    return str;
 }
 
 static VALUE