3 files changed, 12 insertions, 3 deletions
diff --git a/.gitignore b/.gitignore
index eb8afe8..66dd2d0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,5 @@
 /litterbox
 /scoop
 /unscoop
+config.mk
 tags
diff --git a/Linux.mk b/Linux.mk
new file mode 100644
index 0000000..29b7616
--- /dev/null
+++ b/Linux.mk
@@ -0,0 +1,2 @@
+CFLAGS += -D_GNU_SOURCE
+RCS =
diff --git a/README.7 b/README.7
index 3778c2b..910304a 100644
--- a/README.7
+++ b/README.7
@@ -1,4 +1,4 @@
-.Dd January 11, 2020
+.Dd January 12, 2020
 .Dt README 7
 .Os "Causal Agency"
 .
@@ -24,8 +24,14 @@ requires LibreSSL
 and SQLite
 .Pq Fl lsqlite3 ,
 and targets
-.Fx .
-It can also be built on Darwin.
+.Fx
+and Darwin.
+To build on GNU/Linux,
+copy
+.Pa Linux.mk
+to
+.Pa config.mk
+and modify as needed.
 .
 .Sh FILES
 .Bl -tag -width "litterbox.c" -compact