diff --git a/compute_tools/src/compute.rs b/compute_tools/src/compute.rs
index 9ed2fc5143..30310153f9 100644
--- a/compute_tools/src/compute.rs
+++ b/compute_tools/src/compute.rs
@@ -710,7 +710,7 @@ impl ComputeNode {
         info!("running initdb");
         let initdb_bin = Path::new(&self.pgbin).parent().unwrap().join("initdb");
         Command::new(initdb_bin)
-            .args(["-D", pgdata])
+            .args(["--pgdata", pgdata])
             .output()
             .expect("cannot start initdb process");
 
diff --git a/control_plane/src/storage_controller.rs b/control_plane/src/storage_controller.rs
index 0c0e67dff0..36e5e04c86 100644
--- a/control_plane/src/storage_controller.rs
+++ b/control_plane/src/storage_controller.rs
@@ -347,7 +347,7 @@ impl StorageController {
 
             if !tokio::fs::try_exists(&pg_data_path).await? {
                 let initdb_args = [
-                    "-D",
+                    "--pgdata",
                     pg_data_path.as_ref(),
                     "--username",
                     &username(),
diff --git a/libs/postgres_ffi/wal_craft/src/lib.rs b/libs/postgres_ffi/wal_craft/src/lib.rs
index 5c0abda522..9524a5149b 100644
--- a/libs/postgres_ffi/wal_craft/src/lib.rs
+++ b/libs/postgres_ffi/wal_craft/src/lib.rs
@@ -93,9 +93,9 @@ impl Conf {
         );
         let output = self
             .new_pg_command("initdb")?
-            .arg("-D")
+            .arg("--pgdata")
             .arg(&self.datadir)
-            .args(["-U", "postgres", "--no-instructions", "--no-sync"])
+            .args(["--username", "postgres", "--no-instructions", "--no-sync"])
             .output()?;
         debug!("initdb output: {:?}", output);
         ensure!(
diff --git a/pageserver/src/tenant.rs b/pageserver/src/tenant.rs
index 2aebf4f999..e88cda0c9f 100644
--- a/pageserver/src/tenant.rs
+++ b/pageserver/src/tenant.rs
@@ -3887,9 +3887,9 @@ async fn run_initdb(
     let _permit = INIT_DB_SEMAPHORE.acquire().await;
 
     let initdb_command = tokio::process::Command::new(&initdb_bin_path)
-        .args(["-D", initdb_target_dir.as_ref()])
-        .args(["-U", &conf.superuser])
-        .args(["-E", "utf8"])
+        .args(["--pgdata", initdb_target_dir.as_ref()])
+        .args(["--username", &conf.superuser])
+        .args(["--encoding", "utf8"])
         .arg("--no-instructions")
         .arg("--no-sync")
         .env_clear()
diff --git a/test_runner/fixtures/neon_fixtures.py b/test_runner/fixtures/neon_fixtures.py
index 70fe632f49..70a038c960 100644
--- a/test_runner/fixtures/neon_fixtures.py
+++ b/test_runner/fixtures/neon_fixtures.py
@@ -3311,7 +3311,7 @@ class VanillaPostgres(PgProtocol):
         self.pg_bin = pg_bin
         self.running = False
         if init:
-            self.pg_bin.run_capture(["initdb", "-D", str(pgdatadir)])
+            self.pg_bin.run_capture(["initdb", "--pgdata", str(pgdatadir)])
         self.configure([f"port = {port}\n"])
 
     def enable_tls(self):
diff --git a/test_runner/regress/test_wal_acceptor.py b/test_runner/regress/test_wal_acceptor.py
index adfe292c24..c75235a04b 100644
--- a/test_runner/regress/test_wal_acceptor.py
+++ b/test_runner/regress/test_wal_acceptor.py
@@ -772,7 +772,7 @@ class ProposerPostgres(PgProtocol):
     def initdb(self):
         """Run initdb"""
 
-        args = ["initdb", "-U", "cloud_admin", "-D", self.pg_data_dir_path()]
+        args = ["initdb", "--username", "cloud_admin", "--pgdata", self.pg_data_dir_path()]
         self.pg_bin.run(args)
 
     def start(self):