diff --git a/tests/lib/config.nix b/tests/lib/config.nix
index 2cdc9d2..68a1b2e 100644
--- a/tests/lib/config.nix
+++ b/tests/lib/config.nix
@@ -1,3 +1,3 @@
 {
-    security.dhparams.defaultBitSize = 1024; # minimum size required by dovecot
+    security.dhparams.defaultBitSize = 2048; # minimum size required by dovecot
 }