diff --git a/sphinx_gmt/gmtplot.py b/sphinx_gmt/gmtplot.py
index 5524b1c..800e8da 100644
--- a/sphinx_gmt/gmtplot.py
+++ b/sphinx_gmt/gmtplot.py
@@ -434,7 +434,7 @@ def run(self):
         builddir = Path(env.app.doctreedir).parent / "gmtplot_directive"
         # determine how to link to files in builddir from the RST file
         # use os.path.relpath rather than relative_to!
-        builddir_link = Path("/", os.path.relpath(str(builddir), env.app.srcdir))
+        builddir_link = "/" / Path("/", os.path.relpath(str(builddir), env.app.srcdir))
 
         # copy script to builddir
         builddir.mkdir(parents=True, exist_ok=True)