diff --git a/src/main/java/redis/clients/jedis/JedisSentinelPool.java b/src/main/java/redis/clients/jedis/JedisSentinelPool.java
index 2e076b1..0aec8d5 100644
--- a/src/main/java/redis/clients/jedis/JedisSentinelPool.java
+++ b/src/main/java/redis/clients/jedis/JedisSentinelPool.java
@@ -65,6 +65,9 @@ public class JedisSentinelPool extends Pool<Jedis> {
     public JedisSentinelPool(String masterName, Set<String> sentinels,
 	    final GenericObjectPoolConfig poolConfig, int timeout,
 	    final String password, final int database) {
+    // Proper master failover detection dependes on testOnBorrow, so force it here
+    poolConfig.setTestOnBorrow(true);
+
 	this.poolConfig = poolConfig;
 	this.timeout = timeout;
 	this.password = password;