1 files changed, 1 insertions, 0 deletions
diff --git a/object.c b/object.c
index e2e68e07a4..bbc607ea98 100644
--- a/object.c
+++ b/object.c
@@ -3530,6 +3530,7 @@ rb_str_to_dbl_raise(VALUE str, int badcheck, int raise, int *error)
     VALUE v = 0;
 
     StringValue(str);
+    rb_must_asciicompat(str);
     s = RSTRING_PTR(str);
     len = RSTRING_LEN(str);
     if (s) {