diff --git a/Makefile b/Makefile
index adad985..d55a415 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@
 DEPLOY_PATH ?= /export/netapp/korap4dnb
 MAX_THREADS ?= $(shell nproc)
 MAKE ?= make -j $(shell nproc)
-KORAPXML2CONLLU_HEAP ?= $(shell echo "$$(($(MAX_THREADS) * 2100))")
+KORAPXML2CONLLU_HEAP ?= $(shell echo "$$(($(MAX_THREADS) * 2500))")
 KORAPXML2CONLLU ?= java -Xmx$(KORAPXML2CONLLU_HEAP)m -jar lib/korapxml2conllu.jar
 SAXON ?= java -cp lib/saxon9ee.jar:lib/xml-resolver-1.2.jar:lib/textclassifier.jar net.sf.saxon.Transform -expand:off -catalog:"lib/dtds/xhtml11/xhtmlcatalog.xml;lib/dtds/xhtml/dtd/xhtmlcatalog.xml"