diff --git a/apps/mu.subx b/apps/mu.subx
index 778c3e79..c801e329 100644
--- a/apps/mu.subx
+++ b/apps/mu.subx
@@ -4642,7 +4642,7 @@ test-is-identifier-Z:
     5d/pop-to-ebp
     c3/return
 
-test-is-identifier-@:
+test-is-identifier-at:
     # character before 'A' is invalid
     # . prologue
     55/push-ebp
diff --git a/subx.vim b/subx.vim
index f63a13c9..6c6d6acc 100644
--- a/subx.vim
+++ b/subx.vim
@@ -38,7 +38,7 @@ set cpo&vim
 setlocal formatoptions-=t  " allow long lines
 setlocal formatoptions+=c  " but comments should still wrap
 
-setlocal iskeyword+=-,?,<,>,$
+setlocal iskeyword+=-,?,<,>,$,@
 
 syntax match subxH1Comment /# - .*/ | highlight link subxH1Comment Comment
 syntax match subxComment /#\( \.\| - \|? \)\@!.*/ | highlight link subxComment Comment