diff --git a/src/networks/mod.rs b/src/networks/mod.rs
index ebc778f1e9e..8b5117c0d55 100644
--- a/src/networks/mod.rs
+++ b/src/networks/mod.rs
@@ -230,7 +230,8 @@ pub struct ChainConfig {
     pub fip0081_ramp_duration_epochs: u64,
     pub f3_bootstrap_epoch: i64,
     pub f3_initial_power_table: Cid,
-    pub f3_mainfest_server: Option<Cid>,
+    #[cfg_attr(test, arbitrary(gen(|_| Some(libp2p::PeerId::random()))))]
+    pub f3_mainfest_server: Option<libp2p::PeerId>,
 }
 
 impl ChainConfig {
@@ -633,4 +634,12 @@ mod tests {
             "dummydevnet"
         );
     }
+
+    #[test]
+    fn chain_config() {
+        ChainConfig::mainnet();
+        ChainConfig::calibnet();
+        ChainConfig::devnet();
+        ChainConfig::butterflynet();
+    }
 }