diff --git a/autoload/go/path.vim b/autoload/go/path.vim
index d755c34ed6..7b4b76892e 100644
--- a/autoload/go/path.vim
+++ b/autoload/go/path.vim
@@ -91,7 +91,7 @@ function! go#path#Detect()
         " gb vendor plugin
         " (https://github.com/constabulary/gb/tree/master/cmd/gb-vendor)
         let gb_vendor_root = src_path . "vendor" . go#util#PathSep()
-        if !isdirectory(gb_vendor_root) && !go#path#HasPath(gb_vendor_root)
+        if isdirectory(gb_vendor_root) && !go#path#HasPath(gb_vendor_root)
             let gopath = gb_vendor_root . go#util#PathListSep() . gopath
         endif