diff --git a/misc/fuel/fuel-syntax.el b/misc/fuel/fuel-syntax.el
index b0f54dab08..18b5e752f8 100644
--- a/misc/fuel/fuel-syntax.el
+++ b/misc/fuel/fuel-syntax.el
@@ -123,7 +123,7 @@
   (fuel-syntax--second-word-regex '("MIXIN:" "TUPLE:" "SINGLETON:" "UNION:")))
 
 (defconst fuel-syntax--tuple-decl-regex
-  "^TUPLE: +\\([^ ]+\\) +< +\\([^ ]+\\) ")
+  "^TUPLE: +\\([^ \n]+\\) +< +\\([^ \n]+\\)\\_>")
 
 (defconst fuel-syntax--constructor-regex "<[^ >]+>")