README: clarify that the GOPATH source tree is in src
See #37
diff --git a/README.md b/README.md
index f74534a..efcfbc0 100644
--- a/README.md
+++ b/README.md
@@ -143,8 +143,8 @@
Make sure you are using at least Go 1.5, set `GO15VENDOREXPERIMENT=1` if you
are using Go 1.5 and didn't set `GO15VENDOREXPERIMENT=0` if you are using Go 1.6.
-Also note that native vendoring does not work outside the GOPATH tree.
-That is, your project MUST be somewhere in a subfolder of `$GOPATH`.
+Also note that native vendoring does not work outside the GOPATH source tree.
+That is, your project MUST be somewhere in a subfolder of `$GOPATH/src/`.
## License
