diff --git a/src/main/java/redis/clients/jedis/Client.java b/src/main/java/redis/clients/jedis/Client.java
index 6114595..6b0bc9a 100644
--- a/src/main/java/redis/clients/jedis/Client.java
+++ b/src/main/java/redis/clients/jedis/Client.java
@@ -21,7 +21,11 @@ public class Client {
 	this.host = host;
     }
 
-    protected Client sendCommand(String name, String... args) {
+    protected Client sendCommand(String name, String... args)
+	    throws JedisException {
+	if (!isConnected()) {
+	    throw new JedisException("Please connect Jedis before using it.");
+	}
 	protocol.sendCommand(outputStream, name, args);
 	return this;
     }
diff --git a/src/main/java/redis/clients/jedis/Jedis.java b/src/main/java/redis/clients/jedis/Jedis.java
index 8fbc570..3fa89bb 100644
--- a/src/main/java/redis/clients/jedis/Jedis.java
+++ b/src/main/java/redis/clients/jedis/Jedis.java
@@ -23,7 +23,7 @@ public class Jedis extends Client {
 	return sendCommand("GET", key).getBulkReply();
     }
 
-    public void quit() {
+    public void quit() throws JedisException {
 	sendCommand("QUIT");
     }
 
diff --git a/src/test/java/redis/clients/jedis/tests/JedisTest.java b/src/test/java/redis/clients/jedis/tests/JedisTest.java
new file mode 100644
index 0000000..b52173e
--- /dev/null
+++ b/src/test/java/redis/clients/jedis/tests/JedisTest.java
@@ -0,0 +1,14 @@
+package redis.clients.jedis.tests;
+
+import org.junit.Test;
+
+import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisException;
+
+public class JedisTest {
+    @Test(expected = JedisException.class)
+    public void useWithoutConnecting() throws JedisException {
+	Jedis jedis = new Jedis("localhost");
+	jedis.dbSize();
+    }
+}
diff --git a/src/test/java/redis/clients/jedis/tests/commands/ConnectionHandlingCommandsTest.java b/src/test/java/redis/clients/jedis/tests/commands/ConnectionHandlingCommandsTest.java
index 4d41dbe..5af3d82 100644
--- a/src/test/java/redis/clients/jedis/tests/commands/ConnectionHandlingCommandsTest.java
+++ b/src/test/java/redis/clients/jedis/tests/commands/ConnectionHandlingCommandsTest.java
@@ -8,6 +8,7 @@ import org.junit.Ignore;
 import org.junit.Test;
 
 import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisException;
 
 public class ConnectionHandlingCommandsTest extends Assert {
     private Jedis jedis;
@@ -25,7 +26,7 @@ public class ConnectionHandlingCommandsTest extends Assert {
     }
 
     @Test
-    public void quit() {
+    public void quit() throws JedisException {
 	jedis.quit();
     }