diff --git a/src/main/java/io/github/hectorvent/floci/services/s3/S3VirtualHostFilter.java b/src/main/java/io/github/hectorvent/floci/services/s3/S3VirtualHostFilter.java
index cd4fbed8..81e4ee69 100644
--- a/src/main/java/io/github/hectorvent/floci/services/s3/S3VirtualHostFilter.java
+++ b/src/main/java/io/github/hectorvent/floci/services/s3/S3VirtualHostFilter.java
@@ -1,12 +1,11 @@
 package io.github.hectorvent.floci.services.s3;
 
-import jakarta.inject.Inject;
 import jakarta.ws.rs.container.ContainerRequestContext;
 import jakarta.ws.rs.container.ContainerRequestFilter;
 import jakarta.ws.rs.container.PreMatching;
 import jakarta.ws.rs.core.UriBuilder;
 import jakarta.ws.rs.ext.Provider;
-import org.eclipse.microprofile.config.inject.ConfigProperty;
+import org.eclipse.microprofile.config.ConfigProvider;
 
 import java.net.URI;
 import java.util.Optional;
@@ -17,10 +16,15 @@ public class S3VirtualHostFilter implements ContainerRequestFilter {
 
     private final String baseHostname;
 
-    @Inject
-    public S3VirtualHostFilter(
-            @ConfigProperty(name = "floci.base-url", defaultValue = "http://localhost:4566") String baseUrl,
-            @ConfigProperty(name = "floci.hostname") Optional<String> hostname) {
+    // Cannot use @Inject with EmulatorConfig here: @PreMatching JAX-RS filters are
+    // instantiated before CDI beans are fully initialized, causing SRCFG00027 at startup.
+    // Use programmatic ConfigProvider lookup instead.
+    public S3VirtualHostFilter() {
+        String baseUrl = ConfigProvider.getConfig()
+                .getOptionalValue("floci.base-url", String.class)
+                .orElse("http://localhost:4566");
+        Optional<String> hostname = ConfigProvider.getConfig()
+                .getOptionalValue("floci.hostname", String.class);
         String effectiveUrl = hostname
                 .map(h -> baseUrl.replaceFirst("://[^:/]+(:\\d+)?", "://" + h + "$1"))
                 .orElse(baseUrl);
@@ -71,19 +75,21 @@ public void filter(ContainerRequestContext requestContext) {
      * matches a well-known AWS S3 domain pattern (for DNS-redirect setups).
      *
      * Examples with baseHostname="localhost":
-     *   my-bucket.localhost:4566       → "my-bucket"
-     *   my-bucket.localhost            → "my-bucket"
-     *   floci.svc.cluster.local        → null  (no bucket prefix, path-style)
-     *   my-svc.floci.svc.cluster.local → null  (remainder doesn't match "localhost")
+     *   my-bucket.localhost:4566       -> "my-bucket"
+     *   my-bucket.localhost            -> "my-bucket"
+     *   floci.svc.cluster.local        -> null  (no bucket prefix, path-style)
+     *   my-svc.floci.svc.cluster.local -> null  (remainder doesn't match "localhost")
      *
      * Examples with baseHostname="floci.svc.cluster.local":
-     *   my-bucket.floci.svc.cluster.local → "my-bucket"
-     *   floci.svc.cluster.local           → null  (no bucket prefix, path-style)
+     *   my-bucket.floci.svc.cluster.local -> "my-bucket"
+     *   floci.svc.cluster.local           -> null  (no bucket prefix, path-style)
      *
      * Returns null if the host does not match a virtual-hosted pattern.
      */
     static String extractBucket(String host, String baseHostname) {
-        if (host == null) return null;
+        if (host == null) {
+            return null;
+        }
 
         // Strip port if present
         String hostname = stripPort(host);
@@ -117,7 +123,9 @@ static String extractBucket(String host, String baseHostname) {
 
     /** Extracts the hostname (without scheme or port) from a URL string. */
     static String extractHostnameFromUrl(String url) {
-        if (url == null) return null;
+        if (url == null) {
+            return null;
+        }
         try {
             URI uri = URI.create(url);
             return uri.getHost();
@@ -147,11 +155,15 @@ private static boolean isIpv4Address(String hostname) {
         return true;
     }
 
-    /** Returns true for *.s3.amazonaws.com and *.s3.<region>.amazonaws.com domains. */
+    /** Returns true for *.s3.amazonaws.com and *.s3.region.amazonaws.com domains. */
     private static boolean isAwsS3Domain(String remainder) {
-        if ("s3.amazonaws.com".equals(remainder)) return true;
+        if ("s3.amazonaws.com".equals(remainder)) {
+            return true;
+        }
         // s3.<region>.amazonaws.com
-        if (remainder.startsWith("s3.") && remainder.endsWith(".amazonaws.com")) return true;
+        if (remainder.startsWith("s3.") && remainder.endsWith(".amazonaws.com")) {
+            return true;
+        }
         return false;
     }
 }
diff --git a/src/test/java/io/github/hectorvent/floci/services/s3/S3VirtualHostFilterTest.java b/src/test/java/io/github/hectorvent/floci/services/s3/S3VirtualHostFilterTest.java
index 3bd18599..b84616bc 100644
--- a/src/test/java/io/github/hectorvent/floci/services/s3/S3VirtualHostFilterTest.java
+++ b/src/test/java/io/github/hectorvent/floci/services/s3/S3VirtualHostFilterTest.java
@@ -1,5 +1,6 @@
 package io.github.hectorvent.floci.services.s3;
 
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
 import org.junit.jupiter.params.provider.NullSource;
@@ -9,7 +10,7 @@
 
 class S3VirtualHostFilterTest {
 
-    // ── Virtual-hosted style: bucket prefix + matching baseHostname ─────────
+    // --- extractBucket with baseHostname ---
 
     @ParameterizedTest
     @CsvSource({
@@ -33,7 +34,7 @@ void extractsBucketFromVirtualHostedStyle(String host, String baseHostname, Stri
         assertEquals(expectedBucket, S3VirtualHostFilter.extractBucket(host, baseHostname));
     }
 
-    // ── Path-style: service hostname alone — must NOT extract a bucket ───────
+    // --- Path-style: service hostname alone — must NOT extract a bucket ---
 
     @ParameterizedTest
     @CsvSource({
@@ -70,7 +71,14 @@ void returnsNullForNullHost(String host) {
         assertNull(S3VirtualHostFilter.extractBucket(host, "localhost"));
     }
 
-    // ── Hostname extraction from URL ─────────────────────────────────────────
+    @Test
+    void returnsNullForNullBaseHostname() {
+        // Without a baseHostname, only AWS S3 domains should match
+        assertNull(S3VirtualHostFilter.extractBucket("my-bucket.localhost:4566", null));
+        assertEquals("my-bucket", S3VirtualHostFilter.extractBucket("my-bucket.s3.amazonaws.com", null));
+    }
+
+    // --- Hostname extraction from URL ---
 
     @ParameterizedTest
     @CsvSource({
@@ -83,4 +91,9 @@ void returnsNullForNullHost(String host) {
     void extractsHostnameFromUrl(String url, String expectedHostname) {
         assertEquals(expectedHostname, S3VirtualHostFilter.extractHostnameFromUrl(url));
     }
+
+    @Test
+    void extractHostnameFromUrlReturnsNullForNull() {
+        assertNull(S3VirtualHostFilter.extractHostnameFromUrl(null));
+    }
 }