diff --git a/src/main/java/fr/adrienbrault/idea/symfony2plugin/config/yaml/ServiceYamlReference.java b/src/main/java/fr/adrienbrault/idea/symfony2plugin/config/yaml/ServiceYamlReference.java
index 1062d0169..9911c90ee 100644
--- a/src/main/java/fr/adrienbrault/idea/symfony2plugin/config/yaml/ServiceYamlReference.java
+++ b/src/main/java/fr/adrienbrault/idea/symfony2plugin/config/yaml/ServiceYamlReference.java
@@ -18,4 +18,9 @@ public ServiceYamlReference(@NotNull PsiElement psiElement, @NotNull TextRange r
 
         this.serviceId = serviceId;
     }
+
+    @Override
+    public @NotNull Object[] getVariants() {
+        return new Object[0];
+    }
 }
diff --git a/src/test/java/fr/adrienbrault/idea/symfony2plugin/tests/SymfonyLightCodeInsightFixtureTestCase.java b/src/test/java/fr/adrienbrault/idea/symfony2plugin/tests/SymfonyLightCodeInsightFixtureTestCase.java
index 7fb0582ee..81ad9e909 100644
--- a/src/test/java/fr/adrienbrault/idea/symfony2plugin/tests/SymfonyLightCodeInsightFixtureTestCase.java
+++ b/src/test/java/fr/adrienbrault/idea/symfony2plugin/tests/SymfonyLightCodeInsightFixtureTestCase.java
@@ -49,6 +49,9 @@
 import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
+import java.util.stream.Collectors;
+
+import static java.util.function.Function.identity;
 
 /**
  * @author Daniel Espendiller <daniel@espendiller.net>
@@ -87,6 +90,30 @@ public void assertCompletionNotContains(String filename, String configureByText,
         assertFalse(myFixture.getLookupElementStrings().containsAll(Arrays.asList(lookupStrings)));
     }
 
+
+    public void assertCompletionResultsAreUnique(
+        @NotNull LanguageFileType languageFileType,
+        @NotNull String configureByText,
+        @NotNull String... lookupStrings
+    ) {
+        myFixture.configureByText(languageFileType, configureByText);
+        myFixture.completeBasic();
+
+        var results = myFixture.getLookupElementStrings();
+        if (results != null) {
+            var duplicates = results.stream()
+                .filter(result -> Arrays.asList(lookupStrings).contains(result))
+                .collect(Collectors.groupingBy(identity()))
+                .entrySet()
+                .stream()
+                .filter(result -> result.getValue().size() > 1)
+                .map(Map.Entry::getKey)
+                .collect(Collectors.toList());
+
+            assertTrue("The following results are duplicated: " + String.join(", ", duplicates), duplicates.isEmpty());
+        }
+    }
+
     public void assertCompletionNotContains(LanguageFileType languageFileType, String configureByText, String... lookupStrings) {
 
         myFixture.configureByText(languageFileType, configureByText);
diff --git a/src/test/java/fr/adrienbrault/idea/symfony2plugin/tests/dic/yaml/YamlDicCompletionContributorTest.java b/src/test/java/fr/adrienbrault/idea/symfony2plugin/tests/dic/yaml/YamlDicCompletionContributorTest.java
index 46fad38f0..7d87febb0 100644
--- a/src/test/java/fr/adrienbrault/idea/symfony2plugin/tests/dic/yaml/YamlDicCompletionContributorTest.java
+++ b/src/test/java/fr/adrienbrault/idea/symfony2plugin/tests/dic/yaml/YamlDicCompletionContributorTest.java
@@ -61,6 +61,16 @@ public void testServiceCompletion() {
         );
     }
 
+    public void testServiceCompletionResultsAreUnique() {
+        assertCompletionResultsAreUnique(
+            YAMLFileType.YML,
+            "services:\n" +
+            "    newsletter_manager:\n" +
+            "        parent: <caret>\n",
+            "data_collector.router"
+        );
+    }
+
     public void testServiceStaticCompletion() {
 
         assertCompletionContains(YAMLFileType.YML, "services:\n" +