diff --git a/sled-agent/src/instance.rs b/sled-agent/src/instance.rs
index 06f4390c54b..45df6bea2c0 100644
--- a/sled-agent/src/instance.rs
+++ b/sled-agent/src/instance.rs
@@ -1273,12 +1273,13 @@ mod tests {
     use internal_dns::resolver::Resolver;
     use internal_dns::ServiceName;
     use omicron_common::api::external::{
-        ByteCount, Generation, InstanceCpuCount, InstanceState,
+        ByteCount, Generation, Hostname, InstanceCpuCount, InstanceState,
     };
     use omicron_common::api::internal::nexus::InstanceProperties;
     use sled_storage::disk::{RawDisk, SyntheticDisk};
     use sled_storage::manager::FakeStorageManager;
     use std::net::Ipv6Addr;
+    use std::str::FromStr;
     use tokio::sync::watch::Receiver;
     use tokio::time::timeout;
 
@@ -1474,7 +1475,7 @@ mod tests {
             properties: InstanceProperties {
                 ncpus: InstanceCpuCount(1),
                 memory: ByteCount::from_gibibytes_u32(1),
-                hostname: "bert".to_string(),
+                hostname: Hostname::from_str("bert").unwrap(),
             },
             nics: vec![],
             source_nat: SourceNatConfig {