diff --git a/yaml/src/main/java/com/fasterxml/jackson/dataformat/yaml/YAMLFactoryBuilder.java b/yaml/src/main/java/com/fasterxml/jackson/dataformat/yaml/YAMLFactoryBuilder.java
index 6c2b0063..11ff63ac 100644
--- a/yaml/src/main/java/com/fasterxml/jackson/dataformat/yaml/YAMLFactoryBuilder.java
+++ b/yaml/src/main/java/com/fasterxml/jackson/dataformat/yaml/YAMLFactoryBuilder.java
@@ -1,5 +1,6 @@
 package com.fasterxml.jackson.dataformat.yaml;
 
+import com.fasterxml.jackson.core.StreamReadFeature;
 import org.yaml.snakeyaml.DumperOptions;
 
 import com.fasterxml.jackson.core.TSFBuilder;
@@ -226,6 +227,11 @@ public YAMLFactoryBuilder yamlVersionToWrite(DumperOptions.Version v) {
      */
     public YAMLFactoryBuilder loaderOptions(LoaderOptions loaderOptions) {
         _loaderOptions = loaderOptions;
+
+        // If the user wants to block duplicate keys this needs to be set in a different way to work
+        if (!_loaderOptions.isAllowDuplicateKeys()) {
+            enable(StreamReadFeature.STRICT_DUPLICATE_DETECTION);
+        }
         return this;
     }
 
diff --git a/yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/deser/ParserDupHandlingTest.java b/yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/deser/ParserDupHandlingTest.java
index afc5f009..48a26042 100644
--- a/yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/deser/ParserDupHandlingTest.java
+++ b/yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/deser/ParserDupHandlingTest.java
@@ -6,6 +6,7 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.yaml.ModuleTestBase;
 import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
+import org.yaml.snakeyaml.LoaderOptions;
 
 public class ParserDupHandlingTest extends ModuleTestBase
 {
@@ -33,6 +34,17 @@ public void testDupChecksEnabled() throws Exception
         _verifyDupsFail(mapper, YAML_WITH_DUPS, true);
     }
 
+    public void testDupChecksEnabledLoaderOptions() throws Exception
+    {
+        LoaderOptions loaderOptions = new LoaderOptions();
+        loaderOptions.setAllowDuplicateKeys(false);
+        YAMLFactory f = YAMLFactory.builder().loaderOptions(loaderOptions).build();
+
+        ObjectMapper mapper = new ObjectMapper(f);
+        _verifyDupsFail(mapper, YAML_WITH_DUPS, false);
+        _verifyDupsFail(mapper, YAML_WITH_DUPS, true);
+    }
+
     private void _verifyDupsOk(ObjectMapper mapper, String doc, boolean useBytes) throws Exception
     {
         JsonParser p = useBytes ? mapper.getFactory().createParser(new ByteArrayInputStream(doc.getBytes("UTF-8")))