diff --git a/warc-indexer/src/main/java/uk/bl/wa/analyser/WARCPayloadAnalysers.java b/warc-indexer/src/main/java/uk/bl/wa/analyser/WARCPayloadAnalysers.java
index 4fccb2d8..e81c8cde 100644
--- a/warc-indexer/src/main/java/uk/bl/wa/analyser/WARCPayloadAnalysers.java
+++ b/warc-indexer/src/main/java/uk/bl/wa/analyser/WARCPayloadAnalysers.java
@@ -128,7 +128,7 @@ public void analyse(String source, ArchiveRecordHeader header, HTTPHeader httpHe
      * @param header
      * @param content_length
      */
-    private void processContentType(SolrRecord solr, ArchiveRecordHeader header,
+    void processContentType(SolrRecord solr, ArchiveRecordHeader header,
             long content_length, boolean revisit) {
         // Get the current content-type:
         String contentType = (String) solr
@@ -157,7 +157,7 @@ private void processContentType(SolrRecord solr, ArchiveRecordHeader header,
         }
 
         // Allow header MIME
-        if (contentType != null && contentType.isEmpty()) {
+        if (contentType != null && (contentType.isEmpty() || "application/octet-stream".equals(contentType))) {
             if (header.getHeaderFieldKeys()
                     .contains("WARC-Identified-Payload-Type")) {
                 contentType = ((String) header.getHeaderFields()
diff --git a/warc-indexer/src/test/java/uk/bl/wa/analyser/WARCPayloadAnalysersTest.java b/warc-indexer/src/test/java/uk/bl/wa/analyser/WARCPayloadAnalysersTest.java
new file mode 100644
index 00000000..b03606e8
--- /dev/null
+++ b/warc-indexer/src/test/java/uk/bl/wa/analyser/WARCPayloadAnalysersTest.java
@@ -0,0 +1,143 @@
+package uk.bl.wa.analyser;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.HashSet;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.archive.io.ArchiveRecordHeader;
+
+/*
+ * #%L
+ * warc-indexer
+ * %%
+ * Copyright (C) 2013 - 2022 The webarchive-discovery project contributors
+ * %%
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 2 of the
+ * License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public
+ * License along with this program.  If not, see
+ * <http://www.gnu.org/licenses/gpl-2.0.html>.
+ * #L%
+ */
+import com.typesafe.config.Config;
+import com.typesafe.config.ConfigFactory;
+
+import junit.framework.TestCase;
+import uk.bl.wa.solr.SolrFields;
+import uk.bl.wa.solr.SolrRecord;
+import uk.bl.wa.solr.SolrRecordFactory;
+
+public class WARCPayloadAnalysersTest extends TestCase {
+    private static Logger log = LoggerFactory.getLogger(WARCPayloadAnalysersTest.class);
+
+    public void testProcessContentType() {
+        WARCPayloadAnalysers ana = getWARCPayloadAnalysers();
+
+        // For ISSUE-289: https://github.com/ukwa/webarchive-discovery/issues/289
+        // Set up a test with the Header/served content type, but the identified content type is 'application/octet-stream'
+        ArchiveRecordHeader header = new FakeHeader("whatever/localrun-job87-20150219-133227.warc", "video/mp4");
+        SolrRecord solr = SolrRecordFactory.createFactory(null).createRecord();
+        solr.setField(SolrFields.SOLR_CONTENT_TYPE, "application/octet-stream");
+
+        // Determine the full and normalised content types from there:
+        ana.processContentType(solr, header, 1000, false);
+
+        // If other format identification has failed, the served type should win:
+        assertEquals("The final content type should fall back on the served content type", "video/mp4", solr.getFieldValue(SolrFields.FULL_CONTENT_TYPE));
+        assertEquals("The final normalized content type should fall back on the served content type", "video", solr.getFieldValue(SolrFields.SOLR_NORMALISED_CONTENT_TYPE));
+    }
+    private WARCPayloadAnalysers getWARCPayloadAnalysers() {
+        Config conf = ConfigFactory.parseURL(
+                Thread.currentThread().getContextClassLoader().getResource("reference.conf"));
+        return new WARCPayloadAnalysers(conf);
+    }
+
+    private class FakeHeader implements ArchiveRecordHeader {
+        private final String arcPath;
+        private final String mimeType;
+        public FakeHeader(String arcPath, String mimeType) {
+            this.arcPath = arcPath;
+            this.mimeType = mimeType;
+        }
+
+        @Override
+        public String getDate() {
+            return null;
+        }
+
+        @Override
+        public long getLength() {
+            return 0;
+        }
+
+        @Override
+        public long getContentLength() {
+            return 1000;
+        }
+
+        @Override
+        public String getUrl() {
+            return null;
+        }
+
+        @Override
+        public String getMimetype() {
+            return this.mimeType;
+        }
+
+        @Override
+        public String getVersion() {
+            return null;
+        }
+
+        @Override
+        public long getOffset() {
+            return 0;
+        }
+
+        @Override
+        public Object getHeaderValue(String key) {
+            return null;
+        }
+
+        @Override
+        public Set<String> getHeaderFieldKeys() {
+            return new HashSet<String>();
+        }
+
+        @Override
+        public Map<String, Object> getHeaderFields() {
+            return null;
+        }
+
+        @Override
+        public String getReaderIdentifier() {
+            return arcPath;
+        }
+
+        @Override
+        public String getRecordIdentifier() {
+            return null;
+        }
+
+        @Override
+        public String getDigest() {
+            return null;
+        }
+
+        @Override
+        public int getContentBegin() {
+            return 0;
+        }
+    }
+}