diff --git a/pageserver/src/bin/pageserver.rs b/pageserver/src/bin/pageserver.rs
index 87b8354269..21d2d8e4fd 100644
--- a/pageserver/src/bin/pageserver.rs
+++ b/pageserver/src/bin/pageserver.rs
@@ -28,6 +28,8 @@ const DEFAULT_LISTEN_ADDR: &str = "127.0.0.1:64000";
 const DEFAULT_GC_HORIZON: u64 = 64 * 1024 * 1024;
 const DEFAULT_GC_PERIOD: Duration = Duration::from_secs(100);
 
+const DEFAULT_SUPERUSER: &str = "zenith_admin";
+
 /// String arguments that can be declared via CLI or config file
 #[derive(Serialize, Deserialize)]
 struct CfgFileParams {
@@ -96,6 +98,8 @@ impl CfgFileParams {
             gc_horizon,
             gc_period,
 
+            superuser: String::from(DEFAULT_SUPERUSER),
+
             workdir: PathBuf::from("."),
 
             pg_distrib_dir,
diff --git a/pageserver/src/branches.rs b/pageserver/src/branches.rs
index c92c711b21..9071a4adf1 100644
--- a/pageserver/src/branches.rs
+++ b/pageserver/src/branches.rs
@@ -65,6 +65,7 @@ pub fn init_repo(conf: &'static PageServerConf, repo_dir: &Path) -> Result<()> {
     let initdb_path = conf.pg_bin_dir().join("initdb");
     let initdb_otput = Command::new(initdb_path)
         .args(&["-D", tmppath.to_str().unwrap()])
+        .args(&["-U", &conf.superuser])
         .arg("--no-instructions")
         .env_clear()
         .env("LD_LIBRARY_PATH", conf.pg_lib_dir().to_str().unwrap())
diff --git a/pageserver/src/lib.rs b/pageserver/src/lib.rs
index d4cce49f9c..1dfa384760 100644
--- a/pageserver/src/lib.rs
+++ b/pageserver/src/lib.rs
@@ -29,6 +29,7 @@ pub struct PageServerConf {
     pub listen_addr: String,
     pub gc_horizon: u64,
     pub gc_period: Duration,
+    pub superuser: String,
 
     // Repository directory, relative to current working directory.
     // Normally, the page server changes the current working directory
diff --git a/pageserver/src/repository.rs b/pageserver/src/repository.rs
index fd47149327..c4b507c0f2 100644
--- a/pageserver/src/repository.rs
+++ b/pageserver/src/repository.rs
@@ -364,6 +364,7 @@ mod tests {
             gc_horizon: 64 * 1024 * 1024,
             gc_period: Duration::from_secs(10),
             listen_addr: "127.0.0.1:5430".to_string(),
+            superuser: "zenith_admin".to_string(),
             workdir: repo_dir,
             pg_distrib_dir: "".into(),
         };