diff --git a/plugin/src/main/java/io/jenkins/plugins/coverage/targets/CoverageResult.java b/plugin/src/main/java/io/jenkins/plugins/coverage/targets/CoverageResult.java
index bccb5a033..ad3b965c3 100755
--- a/plugin/src/main/java/io/jenkins/plugins/coverage/targets/CoverageResult.java
+++ b/plugin/src/main/java/io/jenkins/plugins/coverage/targets/CoverageResult.java
@@ -828,7 +828,7 @@ public void addAdditionalProperty(final String propertyName, final String value)
     }
 
     public Set<String> getAdditionalProperty(final String propertyName) {
-        return additionalProperties.get(propertyName);
+        return additionalProperties.getOrDefault(propertyName, Collections.emptySet());
     }
 
     /**
diff --git a/plugin/src/test/java/io/jenkins/plugins/coverage/model/CoverageResultTest.java b/plugin/src/test/java/io/jenkins/plugins/coverage/model/CoverageResultTest.java
index b8a7b6791..f8bb16382 100644
--- a/plugin/src/test/java/io/jenkins/plugins/coverage/model/CoverageResultTest.java
+++ b/plugin/src/test/java/io/jenkins/plugins/coverage/model/CoverageResultTest.java
@@ -29,6 +29,13 @@ class CoverageResultTest extends AbstractCoverageTest {
     private static final CoverageElement SOURCE_FILE = CoverageElement.FILE;
     private static final CoverageElement CLASS_NAME = JavaCoverageReportAdapterDescriptor.CLASS;
 
+    @Test
+    void shouldNeverReturnNullForSets() throws CoverageException {
+        CoverageResult project = readReport("jacoco-codingstyle.xml");
+
+        assertThat(project.getAdditionalProperty("not-found")).isEmpty();
+    }
+
     @Test
     void shouldReadJaCoCoResult() throws CoverageException {
         CoverageResult project = readReport("jacoco-codingstyle.xml");