diff --git a/src/main/java/ic/doc/CachedWeatherForecasterBuilder.java b/src/main/java/ic/doc/CachedWeatherForecasterBuilder.java
index 1bb314e..2b18276 100644
--- a/src/main/java/ic/doc/CachedWeatherForecasterBuilder.java
+++ b/src/main/java/ic/doc/CachedWeatherForecasterBuilder.java
@@ -1,9 +1,10 @@
 package ic.doc;
 
+// Builder for CachedWeatherForecaster with default unlimited cache size and 1 hour cache age.
 public class CachedWeatherForecasterBuilder {
   private WeatherForecaster forecaster;
   private Integer maxCacheSize = null;
-  private Integer maxCacheAgeSecs = null;
+  private Integer maxCacheAgeSecs = 3600;
 
   private CachedWeatherForecasterBuilder() {}