diff --git a/router/tests/common/mod.rs b/router/tests/common/mod.rs
index 2b16645fca..1741d27459 100644
--- a/router/tests/common/mod.rs
+++ b/router/tests/common/mod.rs
@@ -37,25 +37,22 @@ pub fn test_context() -> TestContextBuilder {
 
 #[derive(Debug, Default)]
 pub struct TestContextBuilder {
-    namespace_autocreate_policy: Option<NamespaceAutocreatePolicy>,
+    namespace_autocreate_policy: NamespaceAutocreatePolicy,
 }
 
 impl TestContextBuilder {
-    pub fn autocreate_namespace(mut self, enabled: bool) -> Self {
-        self.namespace_autocreate_policy = match self.namespace_autocreate_policy {
-            Some(p) => Some(NamespaceAutocreatePolicy { enabled, ..p }),
-            None => Some(NamespaceAutocreatePolicy::new(true, None)),
+    pub fn with_autocreate_namespace(mut self, enabled: bool) -> Self {
+        self.namespace_autocreate_policy = NamespaceAutocreatePolicy {
+            enabled,
+            ..self.namespace_autocreate_policy
         };
         self
     }
 
-    pub fn autocreate_namespace_retention_period_nanos(mut self, period_nanos: i64) -> Self {
-        self.namespace_autocreate_policy = match self.namespace_autocreate_policy {
-            Some(p) => Some(NamespaceAutocreatePolicy {
-                retention_period_nanos: Some(period_nanos),
-                ..p
-            }),
-            None => Some(NamespaceAutocreatePolicy::new(false, Some(period_nanos))),
+    pub fn with_autocreate_namespace_retention_period_nanos(mut self, period_nanos: i64) -> Self {
+        self.namespace_autocreate_policy = NamespaceAutocreatePolicy {
+            retention_period_nanos: Some(period_nanos),
+            ..self.namespace_autocreate_policy
         };
         self
     }
@@ -67,8 +64,7 @@ impl TestContextBuilder {
 
         test_helpers::maybe_start_logging();
 
-        let namespace_autocreate_policy = namespace_autocreate_policy
-            .unwrap_or_else(|| NamespaceAutocreatePolicy::new(false, None));
+        let namespace_autocreate_policy = namespace_autocreate_policy;
 
         let metrics: Arc<metric::Registry> = Default::default();
 
@@ -78,21 +74,12 @@ impl TestContextBuilder {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Default)]
 struct NamespaceAutocreatePolicy {
     enabled: bool,
     retention_period_nanos: Option<i64>,
 }
 
-impl NamespaceAutocreatePolicy {
-    fn new(enabled: bool, retention_period_nanos: Option<i64>) -> Self {
-        Self {
-            enabled,
-            retention_period_nanos,
-        }
-    }
-}
-
 #[derive(Debug)]
 pub struct TestContext {
     client: Arc<MockWriteClient>,
diff --git a/router/tests/grpc.rs b/router/tests/grpc.rs
index c49c9484b0..bfa3e1f888 100644
--- a/router/tests/grpc.rs
+++ b/router/tests/grpc.rs
@@ -140,7 +140,7 @@ async fn test_namespace_create() {
 #[tokio::test]
 async fn test_namespace_delete() {
     // Initialise a TestContext with implicit namespace creation.
-    let ctx = test_context().autocreate_namespace(true).build().await;
+    let ctx = test_context().with_autocreate_namespace(true).build().await;
 
     const RETENTION: i64 = Duration::from_secs(42 * 60 * 60).as_nanos() as _;
 
diff --git a/router/tests/http.rs b/router/tests/http.rs
index 31651a7f71..0f6ac880d4 100644
--- a/router/tests/http.rs
+++ b/router/tests/http.rs
@@ -16,7 +16,7 @@ pub mod common;
 #[tokio::test]
 async fn test_write_ok() {
     // Create a test context with implicit namespace creation.
-    let ctx = test_context().autocreate_namespace(true).build().await;
+    let ctx = test_context().with_autocreate_namespace(true).build().await;
 
     // Write data inside retention period
     let now = SystemProvider::default()
@@ -91,8 +91,8 @@ async fn test_write_ok() {
 #[tokio::test]
 async fn test_write_outside_retention_period() {
     let ctx = test_context()
-        .autocreate_namespace(true)
-        .autocreate_namespace_retention_period_nanos(TEST_RETENTION_PERIOD_NS)
+        .with_autocreate_namespace(true)
+        .with_autocreate_namespace_retention_period_nanos(TEST_RETENTION_PERIOD_NS)
         .build()
         .await;
 
@@ -120,7 +120,7 @@ async fn test_write_outside_retention_period() {
 
 #[tokio::test]
 async fn test_schema_conflict() {
-    let ctx = test_context().autocreate_namespace(true).build().await;
+    let ctx = test_context().with_autocreate_namespace(true).build().await;
 
     // data inside the retention period
     let now = SystemProvider::default()
@@ -199,7 +199,7 @@ async fn test_rejected_ns() {
 
 #[tokio::test]
 async fn test_schema_limit() {
-    let ctx = test_context().autocreate_namespace(true).build().await;
+    let ctx = test_context().with_autocreate_namespace(true).build().await;
 
     let now = SystemProvider::default()
         .now()
@@ -253,7 +253,7 @@ async fn test_schema_limit() {
 
 #[tokio::test]
 async fn test_write_propagate_ids() {
-    let ctx = test_context().autocreate_namespace(true).build().await;
+    let ctx = test_context().with_autocreate_namespace(true).build().await;
 
     // Create the namespace and a set of tables.
     let ns = ctx
@@ -338,7 +338,7 @@ async fn test_write_propagate_ids() {
 
 #[tokio::test]
 async fn test_delete_unsupported() {
-    let ctx = test_context().autocreate_namespace(true).build().await;
+    let ctx = test_context().with_autocreate_namespace(true).build().await;
 
     // Create the namespace and a set of tables.
     ctx.catalog()