diff --git a/src/main/java/gov/usgs/earthquake/nshmp/DisaggCalc.java b/src/main/java/gov/usgs/earthquake/nshmp/DisaggCalc.java
index 6275df2b5570c0374f7cf15b94c3908bb7ad8664..227d1796a70e4e73523fae99695f41e89a990230 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/DisaggCalc.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/DisaggCalc.java
@@ -64,6 +64,7 @@ public class DisaggCalc {
 
   private static final Gson GSON = new GsonBuilder()
       .serializeSpecialFloatingPointValues()
+      .setPrettyPrinting()
       .serializeNulls()
       .create();