diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..fa4dd1c
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "gnuplot-iostream"]
+	path = gnuplot-iostream
+	url = https://github.com/dstahlke/gnuplot-iostream.git
diff --git a/gnuplot-iostream b/gnuplot-iostream
new file mode 160000
index 0000000..3acbe21
--- /dev/null
+++ b/gnuplot-iostream
@@ -0,0 +1 @@
+Subproject commit 3acbe21c643a482fe8c2923d2812cf2a7b97ebb8