diff --git a/README.md b/README.md
new file mode 100644
index 0000000..49b7cd2
--- /dev/null
+++ b/README.md
@@ -0,0 +1,11 @@
+# go-binary-size
+This repo is companion to an article published here (TODO add link).
+
+Contents :
+* `app`: a Go module intended as an "application" (vs library) with 4 packages compilable as single binaries
+  * `a`, `a2` and `b` depend exclusively on matching packages from `mod1`
+  * `control` depends only on stdlib's `fmt` and is used as a control for what a small Go binary can weigh
+* `mod1`: a Go module intended to represent a library that `app` would include. It contains 3 packages:
+  * `a`: depends on a large external dependency (`github.com/gin-gonic/gin`) in the "normal" files and also depends on some other external dependencies exclusively used in the test files, whether in the same package or in the `a_test` package.
+  * `a2`: same as `a` but doesn't contain test files, to show that test dependencies don't bloat the built binary
+  * `b`: depends only on `fmt`
diff --git a/app/Makefile b/app/Makefile
index 49bdd32..8ced80f 100644
--- a/app/Makefile
+++ b/app/Makefile
@@ -1,8 +1,8 @@
 .PHONY: build
 build:
-	GOARCH=amd64 go build -o ./dist/a ./a
-	GOARCH=amd64 go build -o ./dist/a2 ./a2
-	GOARCH=amd64 go build -o ./dist/b ./b
-	GOARCH=amd64 go build -o ./dist/control ./control
+	GOARCH=amd64 GOOS=darwin go build -o ./dist/a ./a
+	GOARCH=amd64 GOOS=darwin go build -o ./dist/a2 ./a2
+	GOARCH=amd64 GOOS=darwin go build -o ./dist/b ./b
+	GOARCH=amd64 GOOS=darwin go build -o ./dist/control ./control
 	ls -al ./dist
 	shasum -a 256 ./dist/*