diff --git a/nixos/tests/geth.nix b/nixos/tests/geth.nix
index 10cbd6d9038..af8230553bb 100644
--- a/nixos/tests/geth.nix
+++ b/nixos/tests/geth.nix
@@ -31,7 +31,7 @@ import ./make-test-python.nix ({ pkgs, ... }: {
     machine.wait_for_open_port(18545)
 
     machine.succeed(
-        'geth attach --exec "eth.chainId()" http://localhost:8545 | grep \'"0x0"\' '
+        'geth attach --exec eth.blockNumber http://localhost:8545 | grep \'^0$\' '
     )
 
     machine.succeed(