diff --git a/rebar.config b/rebar.config
index ea69915..d40871f 100644
--- a/rebar.config
+++ b/rebar.config
@@ -1,6 +1,5 @@
 {erl_opts, [warnings_as_errors,
             {platform_define, "18", old_rand},
-            {platform_define, "17", old_rand},
             {platform_define, "^R", old_rand},
             {platform_define, "^R", no_sync}]}.