diff --git a/plugin/src/main/java/org/owasp/benchmarkutils/score/Configuration.java b/plugin/src/main/java/org/owasp/benchmarkutils/score/Configuration.java
index 3a45a04..f60a4f7 100644
--- a/plugin/src/main/java/org/owasp/benchmarkutils/score/Configuration.java
+++ b/plugin/src/main/java/org/owasp/benchmarkutils/score/Configuration.java
@@ -22,6 +22,7 @@
 import java.io.InputStream;
 import java.io.SequenceInputStream;
 import java.util.Map;
+import org.yaml.snakeyaml.LoaderOptions;
 import org.yaml.snakeyaml.Yaml;
 
 /**
@@ -76,7 +77,30 @@ public class Configuration {
 
     public final Report report;
 
-    private static final Yaml yaml = new Yaml();
+    private static Yaml yaml = new Yaml(defaultLoaderOptions());
+
+    /**
+     * Custom loader options to disable warning for duplicate key (which is not helpful, because
+     * it's intended behaviour to merge keys from multiple files)
+     */
+    private static LoaderOptions defaultLoaderOptions() {
+        LoaderOptions loaderOptions = new LoaderOptions();
+
+        loaderOptions.setAllowDuplicateKeys(true);
+
+        return loaderOptions;
+    }
+
+    /**
+     * Used to disable warnings on duplicate keys. Occurs when providing an additional configuration file.
+     */
+    static void disableWarnOnDuplicateKeys() {
+        LoaderOptions loaderOptions = defaultLoaderOptions();
+
+        loaderOptions.setWarnOnDuplicateKeys(false);
+
+        yaml = new Yaml(loaderOptions);
+    }
 
     public static Configuration fromDefaultConfig() {
         return fromInputStream(resourceAsStream(DEFAULT_CONFIG), DEFAULT_SUCCESS_MESSAGE);
diff --git a/plugin/src/test/java/org/owasp/benchmarkutils/score/BenchmarkScoreTest.java b/plugin/src/test/java/org/owasp/benchmarkutils/score/BenchmarkScoreTest.java
index 87110fe..c7292db 100644
--- a/plugin/src/test/java/org/owasp/benchmarkutils/score/BenchmarkScoreTest.java
+++ b/plugin/src/test/java/org/owasp/benchmarkutils/score/BenchmarkScoreTest.java
@@ -28,13 +28,14 @@
 
 public class BenchmarkScoreTest {
 
-    private static final String SEP = System.getProperty("line.separator");
+    private static final String SEP = System.lineSeparator();
     private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
     private final PrintStream originalOut = System.out;
 
     @BeforeEach
     public void setUpStreams() {
         System.setOut(new PrintStream(outContent));
+        Configuration.disableWarnOnDuplicateKeys();
     }
 
     @AfterEach
diff --git a/plugin/src/test/java/org/owasp/benchmarkutils/score/ConfigurationTest.java b/plugin/src/test/java/org/owasp/benchmarkutils/score/ConfigurationTest.java
index 5a4ad62..286b4c3 100644
--- a/plugin/src/test/java/org/owasp/benchmarkutils/score/ConfigurationTest.java
+++ b/plugin/src/test/java/org/owasp/benchmarkutils/score/ConfigurationTest.java
@@ -57,6 +57,8 @@ public void setUp() {
 
         out = new ByteArrayOutputStream();
         System.setOut(new PrintStream(out));
+
+        Configuration.disableWarnOnDuplicateKeys();
     }
 
     @Test