diff --git a/core/src/main/java/com/predic8/membrane/core/http/Header.java b/core/src/main/java/com/predic8/membrane/core/http/Header.java
index cb8a432f3..4ab026b22 100644
--- a/core/src/main/java/com/predic8/membrane/core/http/Header.java
+++ b/core/src/main/java/com/predic8/membrane/core/http/Header.java
@@ -33,7 +33,7 @@
 /**
  * The headers of an HTTP message.
  */
-public class Header {
+public class Header implements Map<String,String> {
 
 	private static final Logger log = LoggerFactory.getLogger(Header.class.getName());
 
@@ -431,10 +431,69 @@ public static long parseKeepAliveHeader(String keepAliveHeaderValue, String para
 		return Long.parseLong(m.group(1));
 	}
 
+	@Override
+	public int size() {
+		return fields.size();
+	}
+
+	@Override
+	public boolean isEmpty() {
+		return fields.isEmpty();
+	}
+
+	@Override
+	public boolean containsKey(Object key) {
+		return false;
+	}
+
+	@Override
+	public boolean containsValue(Object value) {
+		return false;
+	}
+
+	@Override
+	public String get(Object key) {
+		return null;
+	}
+
+	@org.jetbrains.annotations.Nullable
+	@Override
+	public String put(String key, String value) {
+		return null;
+	}
+
+	@Override
+	public String remove(Object key) {
+		return null;
+	}
+
+	@Override
+	public void putAll(@org.jetbrains.annotations.NotNull Map<? extends String, ? extends String> m) {
+
+	}
+
 	public void clear() {
 		fields.clear();
 	}
 
+	@org.jetbrains.annotations.NotNull
+	@Override
+	public Set<String> keySet() {
+		return null;
+	}
+
+	@org.jetbrains.annotations.NotNull
+	@Override
+	public Collection<String> values() {
+		return null;
+	}
+
+	@org.jetbrains.annotations.NotNull
+	@Override
+	public Set<Entry<String, String>> entrySet() {
+		return null;
+	}
+
 	public void setNoCacheResponseHeaders() {
 		setValue(EXPIRES, "Tue, 03 Jul 2001 06:00:00 GMT");
 		setValue(CACHE_CONTROL, "no-store, no-cache, must-revalidate, max-age=0");
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/ratelimit/RateLimitInterceptor.java b/core/src/main/java/com/predic8/membrane/core/interceptor/ratelimit/RateLimitInterceptor.java
index 4879c3037..11ded9b65 100644
--- a/core/src/main/java/com/predic8/membrane/core/interceptor/ratelimit/RateLimitInterceptor.java
+++ b/core/src/main/java/com/predic8/membrane/core/interceptor/ratelimit/RateLimitInterceptor.java
@@ -21,6 +21,7 @@
 import com.predic8.membrane.core.lang.spel.*;
 import org.slf4j.*;
 import org.springframework.expression.*;
+import org.springframework.expression.spel.*;
 import org.springframework.expression.spel.standard.*;
 
 import java.time.*;
@@ -92,12 +93,19 @@ public RateLimitInterceptor(Duration requestLimitDuration, int requestLimit) {
 
     @Override
     public Outcome handleRequest(Exchange exc) throws Exception {
-        if (!strategy.isRequestLimitReached(getKey(exc)))
-            return CONTINUE;
+
+        try {
+            if (!strategy.isRequestLimitReached(getKey(exc)))
+                return CONTINUE;
+        } catch (SpelEvaluationException e) {
+            log.error("Cannot evaluate keyExpression '{}' cause is {}",keyExpression,e.getMessage());
+            exc.setResponse(createProblemDetails(500, "/internal-error", "Internal Server Error"));
+            return RETURN;
+        }
 
         Map<String,Object> details = new HashMap<>();
         details.put("message","The quota of the ratelimiter is exceeded. Try again in %s seconds.".formatted(strategy.getLimitReset(exc.getRemoteAddrIp())));
-        exc.setResponse(createProblemDetails(429, "/ratelimiter/exceeded", "Rate Limit is Exceeded", details));
+        exc.setResponse(createProblemDetails(429, "/ratelimiter/exceeded", "Rate limit is exceeded", details));
         setHeaderRateLimitFieldsOnResponse(exc);
 
         return RETURN;
diff --git a/core/src/test/java/com/predic8/membrane/core/lang/spel/ExchangeEvaluationContextTest.java b/core/src/test/java/com/predic8/membrane/core/lang/spel/ExchangeEvaluationContextTest.java
new file mode 100644
index 000000000..a064b5057
--- /dev/null
+++ b/core/src/test/java/com/predic8/membrane/core/lang/spel/ExchangeEvaluationContextTest.java
@@ -0,0 +1,32 @@
+package com.predic8.membrane.core.lang.spel;
+
+import com.predic8.membrane.core.exchange.*;
+import com.predic8.membrane.core.http.*;
+import org.apache.http.client.methods.*;
+import org.junit.jupiter.api.*;
+import org.springframework.expression.*;
+import org.springframework.expression.spel.standard.*;
+
+import java.net.*;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ExchangeEvaluationContextTest {
+
+    Exchange exc;
+
+    @BeforeEach
+    void setup() throws URISyntaxException {
+        exc = new Request.Builder().header("Authentication","foo").buildExchange();
+
+
+    }
+
+    @Test
+    void getMethod() {
+
+        Expression expression = new SpelExpressionParser().parseExpression("headers.Authentication");
+
+        expression.getValue(new ExchangeEvaluationContext(exc, exc.getRequest()).getStandardEvaluationContext(), String.class);
+    }
+}
\ No newline at end of file
diff --git a/distribution/examples/rateLimiter/proxies.xml b/distribution/examples/rateLimiter/proxies.xml
index 16d443a23..31d9d220c 100644
--- a/distribution/examples/rateLimiter/proxies.xml
+++ b/distribution/examples/rateLimiter/proxies.xml
@@ -6,10 +6,10 @@
 
 	<router>
 
-		<serviceProxy port="2000">
+		<api port="2000">
 			<rateLimiter requestLimit="3" requestLimitDuration="PT30S"/>
 			<target host="www.google.de" port="80" />
-		</serviceProxy>
+		</api>
 
 	</router>