diff --git a/.npmignore b/.npmignore
index 3af34bded4a..d295e9bbd77 100644
--- a/.npmignore
+++ b/.npmignore
@@ -1,5 +1,6 @@
 built
 doc
+lib/README.md
 scripts
 src
 tests
diff --git a/lib/README.md b/lib/README.md
new file mode 100644
index 00000000000..b2837989505
--- /dev/null
+++ b/lib/README.md
@@ -0,0 +1,4 @@
+# Read this!
+
+These files are not meant to be edited by hand.
+If you need to make modifications, the respective files should be changed within the repository's top-level `src` directory.
\ No newline at end of file
diff --git a/src/lib/README.md b/src/lib/README.md
new file mode 100644
index 00000000000..cbf80e4d0da
--- /dev/null
+++ b/src/lib/README.md
@@ -0,0 +1,8 @@
+# Read this!
+
+The files within this directory are used to generate `lib.d.ts` and `lib.es6.d.ts`.
+
+## Generated files
+
+Any files ending in `.generated.d.ts` aren't mean to be edited by hand.
+If you need to make changes to such files, make a change to the input files for our [library generator](https://github.com/Microsoft/TSJS-lib-generator).