diff --git a/httpclient/src/main/java/org/apache/http/impl/client/InternalHttpClient.java b/httpclient/src/main/java/org/apache/http/impl/client/InternalHttpClient.java
index 970260fcb..cf0334e81 100644
--- a/httpclient/src/main/java/org/apache/http/impl/client/InternalHttpClient.java
+++ b/httpclient/src/main/java/org/apache/http/impl/client/InternalHttpClient.java
@@ -66,7 +66,6 @@ import org.apache.http.params.HttpParamsNames;
 import org.apache.http.protocol.BasicHttpContext;
 import org.apache.http.protocol.HttpContext;
 import org.apache.http.util.Args;
-import org.apache.http.util.Asserts;
 
 /**
  * Internal class.
@@ -122,7 +121,6 @@ class InternalHttpClient extends CloseableHttpClient {
         if (host == null) {
             host = (HttpHost) request.getParams().getParameter(ClientPNames.DEFAULT_HOST);
         }
-        Asserts.notNull(host, "Target host");
         return this.routePlanner.determineRoute(host, request, context);
     }
 
diff --git a/httpclient/src/main/java/org/apache/http/impl/conn/DefaultRoutePlanner.java b/httpclient/src/main/java/org/apache/http/impl/conn/DefaultRoutePlanner.java
index 0dce040b0..b56d2f8ed 100644
--- a/httpclient/src/main/java/org/apache/http/impl/conn/DefaultRoutePlanner.java
+++ b/httpclient/src/main/java/org/apache/http/impl/conn/DefaultRoutePlanner.java
@@ -32,6 +32,7 @@ import java.net.InetAddress;
 import org.apache.http.HttpException;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
+import org.apache.http.ProtocolException;
 import org.apache.http.annotation.Immutable;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.protocol.HttpClientContext;
@@ -64,8 +65,10 @@ public class DefaultRoutePlanner implements HttpRoutePlanner {
             final HttpHost host,
             final HttpRequest request,
             final HttpContext context) throws HttpException {
-        Args.notNull(host, "Target host");
         Args.notNull(request, "Request");
+        if (host == null) {
+            throw new ProtocolException("Target host is not specified");
+        }
         final HttpClientContext clientContext = HttpClientContext.adapt(context);
         final RequestConfig config = clientContext.getRequestConfig();
         final InetAddress local = config.getLocalAddress();
diff --git a/httpclient/src/test/java/org/apache/http/impl/conn/TestDefaultRoutePlanner.java b/httpclient/src/test/java/org/apache/http/impl/conn/TestDefaultRoutePlanner.java
index 20988fc54..611d0e721 100644
--- a/httpclient/src/test/java/org/apache/http/impl/conn/TestDefaultRoutePlanner.java
+++ b/httpclient/src/test/java/org/apache/http/impl/conn/TestDefaultRoutePlanner.java
@@ -30,6 +30,7 @@ package org.apache.http.impl.conn;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
 import org.apache.http.HttpVersion;
+import org.apache.http.ProtocolException;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.protocol.HttpClientContext;
 import org.apache.http.conn.SchemePortResolver;
@@ -102,4 +103,12 @@ public class TestDefaultRoutePlanner {
         Mockito.verify(schemePortResolver, Mockito.never()).resolve(Mockito.<HttpHost>any());
     }
 
+    @Test(expected= ProtocolException.class)
+    public void testNullTarget() throws Exception {
+        final HttpRequest request = new BasicHttpRequest("GET", "/", HttpVersion.HTTP_1_1);
+
+        final HttpContext context = new BasicHttpContext();
+        routePlanner.determineRoute(null, request, context);
+    }
+
 }