diff --git a/src/cactus/progressive/cactus_progressive.py b/src/cactus/progressive/cactus_progressive.py
index 8df70f14c..62a110686 100755
--- a/src/cactus/progressive/cactus_progressive.py
+++ b/src/cactus/progressive/cactus_progressive.py
@@ -281,7 +281,7 @@ def run(self, fileStore):
                                      disk=self.configWrapper.getExportHalDisk(),
                                      preemptable=False).rv()
 
-def exportHal(job, project, event=None, cacheBytes=None, cacheMDC=None, cacheRDC=None, cacheW0=None, chunk=None, deflate=None, inMemory=False):
+def exportHal(job, project, event=None, cacheBytes=None, cacheMDC=None, cacheRDC=None, cacheW0=None, chunk=None, deflate=None, inMemory=True):
 
     HALPath = "tmp_alignment.hal"