diff --git a/doc_src/index.hdr.in b/doc_src/index.hdr.in
index a31e12917..685a2070f 100644
--- a/doc_src/index.hdr.in
+++ b/doc_src/index.hdr.in
@@ -1170,7 +1170,7 @@ If you want to add the directory `~/linux/bin` to your PATH variable when using
 
 \fish
 if status --is-login
-    set PATH $PATH ~/linux/bin
+    set -x PATH $PATH ~/linux/bin
 end
 \endfish