diff -urEbwB fop-2.5/fop/build.xml fop-2.5/fop/build.xml
--- fop-2.5/fop/build.xml	2020-05-05 11:42:05.000000000 +0200
+++ fop-2.5/fop/build.xml	2020-06-03 11:09:17.026418161 +0200
@@ -207,7 +207,7 @@
   <property name="lib.dir" value="${basedir}/lib"/>
   <property name="user.hyph.dir" value="${basedir}/hyph"/>
   <property name="unidata.dir" value="${basedir}/UNIDATA"/>
-  <property name="hyph.stacksize" value="512k"/>
+  <property name="hyph.stacksize" value="1M"/>
   <property name="test.dir" value="${basedir}/test"/>
   <property name="test.java.dir" value="${src.dir}/test/java"/>
   <property name="test.resources.dir" value="${src.dir}/test/resources"/>