1 files changed, 1 insertions, 0 deletions
diff --git a/numeric.c b/numeric.c
index ffa576149e..5ef02336db 100644
--- a/numeric.c
+++ b/numeric.c
@@ -5182,6 +5182,7 @@ Init_Numeric(void)
     rb_cFixnum = rb_cInteger;
 #endif
     rb_define_const(rb_cObject, "Fixnum", rb_cInteger);
+    rb_deprecate_constant(rb_cObject, "Fixnum");
 
     rb_cFloat  = rb_define_class("Float", rb_cNumeric);