diff --git a/src/main/java/br/ufrgs/inf/prosoft/cache/CachePerformance.java b/src/main/java/br/ufrgs/inf/prosoft/cache/CachePerformance.java
index d8b1af8..9897eb5 100644
--- a/src/main/java/br/ufrgs/inf/prosoft/cache/CachePerformance.java
+++ b/src/main/java/br/ufrgs/inf/prosoft/cache/CachePerformance.java
@@ -18,7 +18,9 @@ import java.util.logging.Logger;
*/
public class CachePerformance {
- private static final String CACHE_EVENTS = System.getenv("CACHE_EVENTS") != null && !System.getenv("CACHE_EVENTS").isEmpty() ? System.getenv("CACHE_EVENTS") : null;
+ private static final String CACHE_EVENTS
+ = System.getenv("CACHE_EVENTS") != null && !System.getenv("CACHE_EVENTS").isEmpty() && !System.getenv("CACHE_EVENTS").equals("null")
+ ? System.getenv("CACHE_EVENTS") : null;
private int misses;
private int additions;
private double bytesAdded;