diff --git a/mix.exs b/mix.exs
index 791b276c6..b620e522a 100644
--- a/mix.exs
+++ b/mix.exs
@@ -81,7 +81,8 @@ defmodule Ejabberd.MixProject do
              if_version_below(~c"23", [{:d, :USE_OLD_CRYPTO_HMAC}]) ++
              if_version_below(~c"23", [{:d, :USE_OLD_PG2}]) ++
              if_version_below(~c"24", [{:d, :COMPILER_REPORTS_ONLY_LINES}]) ++
-             if_version_below(~c"24", [{:d, :SYSTOOLS_APP_DEF_WITHOUT_OPTIONAL}])
+             if_version_below(~c"24", [{:d, :SYSTOOLS_APP_DEF_WITHOUT_OPTIONAL}]) ++
+             if_version_below(~c"25", [{:d, :OTP_BELOW_25}])
     defines = for {:d, value} <- result, do: {:d, value}
     result ++ [{:d, :ALL_DEFS, defines}]
   end