diff -ruN /usr/ports/cad/calculix-ccx/files/patch-Makefile calculix-ccx/files/patch-Makefile
--- /usr/ports/cad/calculix-ccx/files/patch-Makefile	2020-08-20 13:50:38.383663000 +0200
+++ calculix-ccx/files/patch-Makefile	2020-09-15 01:47:42.113502000 +0200
@@ -4,7 +4,7 @@
  
 -CFLAGS = -Wall -O2  -I ../../../SPOOLES.2.2 -DARCH="Linux" -DSPOOLES -DARPACK -DMATRIXSTORAGE -DNETWORKOUT
 -FFLAGS = -Wall -O2
-+CFLAGS += -O2  -I%%LOCALBASE%%/include -I%%LOCALBASE%%/include/spooles -DARCH="FreeBSD" -DSPOOLES -DARPACK -DMATRIXSTORAGE -DNETWORKOUT
++CFLAGS += -O2  -I%%LOCALBASE%%/include -I%%LOCALBASE%%/include/spooles -DARCH="FreeBSD" -DSPOOLES -DARPACK -DMATRIXSTORAGE -DNETWORKOUT -DUSE_MT=1
 +FFLAGS += -O2
  
 -CC=cc
diff -ruN /usr/ports/cad/calculix-ccx/pkg-message calculix-ccx/pkg-message
--- /usr/ports/cad/calculix-ccx/pkg-message	2020-01-04 22:46:09.165132000 +0100
+++ calculix-ccx/pkg-message	2020-09-15 01:52:50.932010000 +0200
@@ -2,8 +2,8 @@
 { type: install
   message: <<EOM
 Spooles: by default the single-threaded solver is used unless you set the
-CCX_NPROC_EQUATION_SOLVER environment variable with the number of
-cores you want to use.
+OMP_NUM_THREADS environment variable with the number of cores you want to use.
+e.g: /usr/bin/time -h env OMP_NUM_THREADS=4 ccx -i foo
 EOM
 }
 ]