diff --git a/commons/src/main/java/org/archive/io/arc/WriterPoolSettingsData.java b/commons/src/main/java/org/archive/io/arc/WriterPoolSettingsData.java
index bb568ca5..173f84a6 100644
--- a/commons/src/main/java/org/archive/io/arc/WriterPoolSettingsData.java
+++ b/commons/src/main/java/org/archive/io/arc/WriterPoolSettingsData.java
@@ -30,8 +30,8 @@ public class WriterPoolSettingsData implements WriterPoolSettings {
     List<File> outputDirs;
     boolean compress;
     List<String> metadata;
-    boolean frequentFlushes;
-    int writeBufferSize;
+    boolean frequentFlushes = true;
+    int writeBufferSize = 16*1024;
     
     public WriterPoolSettingsData(String prefix, String template,
             long maxFileSizeBytes, boolean compress, List<File> outputDirs,