diff --git a/misc/fuel/fuel-syntax.el b/misc/fuel/fuel-syntax.el
index 49e7788b2f..0d85cf897e 100644
--- a/misc/fuel/fuel-syntax.el
+++ b/misc/fuel/fuel-syntax.el
@@ -85,7 +85,7 @@
   "^M: +\\([^ ]+\\) +\\([^ ]+\\)")
 
 (defconst fuel-syntax--number-regex
-  "\\(\\+\\|-\\)?\\([0-9]+\\.?[0-9]*\\|\\.[0-9]+\\)\\([eE]\\(\\+\\|-\\)?[0-9]+\\)?")
+  "\\_<\\(\\+\\|-\\)?\\([0-9]+\\.?[0-9]*\\|\\.[0-9]+\\)\\([eE]\\(\\+\\|-\\)?[0-9]+\\)?\\_>")
 
 (defconst fuel-syntax--word-definition-regex
   (fuel-syntax--second-word-regex