diff --git a/src/main/java/fr/adrienbrault/idea/symfony2plugin/config/yaml/YamlLanguageInjector.java b/src/main/java/fr/adrienbrault/idea/symfony2plugin/config/yaml/YamlLanguageInjector.java
new file mode 100644
index 000000000..a430e8bc9
--- /dev/null
+++ b/src/main/java/fr/adrienbrault/idea/symfony2plugin/config/yaml/YamlLanguageInjector.java
@@ -0,0 +1,76 @@
+package fr.adrienbrault.idea.symfony2plugin.config.yaml;
+
+import com.intellij.lang.injection.MultiHostInjector;
+import com.intellij.lang.injection.MultiHostRegistrar;
+import com.intellij.openapi.util.TextRange;
+import com.intellij.patterns.PlatformPatterns;
+import com.intellij.psi.ElementManipulators;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFile;
+import fr.adrienbrault.idea.symfony2plugin.Symfony2ProjectComponent;
+import fr.adrienbrault.idea.symfony2plugin.expressionLanguage.ExpressionLanguage;
+import fr.adrienbrault.idea.symfony2plugin.util.yaml.YamlHelper;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.yaml.psi.YAMLPsiElement;
+import org.jetbrains.yaml.psi.YAMLQuotedText;
+
+import java.util.Collections;
+import java.util.List;
+
+public class YamlLanguageInjector implements MultiHostInjector {
+
+    private static final String EXPRESSION_LANGUAGE_PREFIX = "@=";
+
+    @Override
+    public void getLanguagesToInject(@NotNull MultiHostRegistrar registrar, @NotNull PsiElement context) {
+        if (!Symfony2ProjectComponent.isEnabled(context.getProject())) {
+            return;
+        }
+
+        if (!(context instanceof YAMLQuotedText)) {
+            return ;
+        }
+
+        var file = context.getContainingFile();
+        var element = (YAMLQuotedText) context;
+        var value = element.getTextValue();
+
+        if (YamlHelper.isServicesFile(file) && isExpressionLanguageString(value) && isExpressionLanguageStringAllowed(element)) {
+            registrar
+                .startInjecting(ExpressionLanguage.INSTANCE)
+                .addPlace(null, null, element, getExpressionLanguageTextRange(value))
+                .doneInjecting();
+        } else if (YamlHelper.isRoutingFile(file) && isInsideRouteConditionKey(element)) {
+            registrar
+                .startInjecting(ExpressionLanguage.INSTANCE)
+                .addPlace(null, null, element, ElementManipulators.getValueTextRange(element))
+                .doneInjecting();
+        }
+    }
+
+    @NotNull
+    @Override
+    public List<? extends Class<? extends PsiElement>> elementsToInjectIn() {
+        return Collections.singletonList(YAMLQuotedText.class);
+    }
+
+    private boolean isExpressionLanguageString(@NotNull String str) {
+        return str.startsWith(EXPRESSION_LANGUAGE_PREFIX) && str.length() > EXPRESSION_LANGUAGE_PREFIX.length();
+    }
+
+    private boolean isExpressionLanguageStringAllowed(@NotNull YAMLPsiElement element) {
+        return PlatformPatterns.and(
+            YamlElementPatternHelper.getInsideKeyValue("services"),
+            YamlElementPatternHelper.getInsideKeyValue("arguments", "properties", "calls", "configurator")
+        ).accepts(element);
+    }
+
+    @NotNull
+    private TextRange getExpressionLanguageTextRange(@NotNull String str) {
+        return new TextRange(EXPRESSION_LANGUAGE_PREFIX.length() + 1, str.length() + 1);
+    }
+
+    private boolean isInsideRouteConditionKey(@NotNull YAMLPsiElement element) {
+        return  YamlElementPatternHelper.getInsideKeyValue("condition").accepts(element);
+    }
+}
diff --git a/src/main/resources/META-INF/plugin.xml b/src/main/resources/META-INF/plugin.xml
index 2a2fff93a..76609d035 100644
--- a/src/main/resources/META-INF/plugin.xml
+++ b/src/main/resources/META-INF/plugin.xml
@@ -252,6 +252,8 @@
         <codeInsight.parameterNameHints language="yaml" implementationClass="fr.adrienbrault.idea.symfony2plugin.dic.ServiceArgumentParameterHintsProvider"/>
 
         <multiHostInjector implementation="fr.adrienbrault.idea.symfony2plugin.lang.ParameterLanguageInjector"/>
+        <multiHostInjector implementation="fr.adrienbrault.idea.symfony2plugin.config.yaml.YamlLanguageInjector" />
+
         <iconProvider implementation="fr.adrienbrault.idea.symfony2plugin.twig.icon.TwigIconProvider"/>
 
         <localInspection groupPath="Symfony" shortName="PhpRouteMissingInspection" displayName="Route Missing"