diff --git a/share/functions/prompt_hostname.fish b/share/functions/prompt_hostname.fish
index dcb733578..01e510785 100644
--- a/share/functions/prompt_hostname.fish
+++ b/share/functions/prompt_hostname.fish
@@ -1,3 +1,3 @@
 function prompt_hostname --description 'short hostname for the prompt'
-    string replace -r "\..*" "" $hostname
+    string replace -r -- "\..*" "" $hostname
 end