diff --git a/process.c b/process.c
index 793ab47700..dd23148a00 100644
--- a/process.c
+++ b/process.c
@@ -7975,6 +7975,7 @@ InitVM_process(void)
 #if defined(HAVE_TIMES) || defined(_WIN32)
     rb_cProcessTms = rb_struct_define_under(rb_mProcess, "Tms", "utime", "stime", "cutime", "cstime", NULL);
     rb_define_const(rb_cStruct, "Tms", rb_cProcessTms); /* for the backward compatibility */
+    rb_deprecate_constant(rb_cStruct, "Tms");
 #endif
 
     SAVED_USER_ID = geteuid();