diff --git a/runtime/syntax/fish.yaml b/runtime/syntax/fish.yaml
index 73da226886..a1be57405d 100644
--- a/runtime/syntax/fish.yaml
+++ b/runtime/syntax/fish.yaml
@@ -2,7 +2,7 @@ filetype: fish
 
 detect:
     filename: "\\.fish$"
-    header: "^#!.*/(env +)?fish( |$)"
+    header: "^#!.*/(env +(-S +)?)?fish( |$)"
 
 rules:
       # Numbers