Index: head/tests/sys/kern/coredump_phnum_test.sh
===================================================================
--- head/tests/sys/kern/coredump_phnum_test.sh
+++ head/tests/sys/kern/coredump_phnum_test.sh
@@ -45,10 +45,12 @@
 	ulimit -c '$(ulimit -c)'
 	sysctl kern.coredump=$(sysctl -n kern.coredump)
 	sysctl kern.corefile='$(sysctl -n kern.corefile)'
+	sysctl kern.compress_user_cores='$(sysctl -n kern.compress_user_cores)'
 EOF
 
 	ulimit -c unlimited
 	sysctl kern.coredump=1
+	sysctl kern.compress_user_cores=0
 	sysctl kern.corefile="$(pwd)/coredump_phnum_helper.core"
 
 	atf_check -s signal:sigabrt "$(atf_get_srcdir)/coredump_phnum_helper"