diff --git a/misc/fuel/fuel-font-lock.el b/misc/fuel/fuel-font-lock.el
index 10561ded68..1dee0326ae 100644
--- a/misc/fuel/fuel-font-lock.el
+++ b/misc/fuel/fuel-font-lock.el
@@ -88,6 +88,9 @@
   `((,fuel-syntax--stack-effect-regex . 'factor-font-lock-stack-effect)
     (,fuel-syntax--brace-words-regex 1 'factor-font-lock-parsing-word)
     (,fuel-syntax--vocab-ref-regexp  2 'factor-font-lock-vocabulary-name)
+    (,fuel-syntax--constructor-regex (1 'factor-font-lock-word)
+                                     (2 'factor-font-lock-type-name)
+                                     (3 'factor-font-lock-invalid-syntax nil t))
     (,fuel-syntax--declaration-words-regex . 'factor-font-lock-declaration)
     (,fuel-syntax--word-definition-regex 2 'factor-font-lock-word)
     (,fuel-syntax--alias-definition-regex (1 'factor-font-lock-word)
diff --git a/misc/fuel/fuel-syntax.el b/misc/fuel/fuel-syntax.el
index 4112e3507d..c2b7391383 100644
--- a/misc/fuel/fuel-syntax.el
+++ b/misc/fuel/fuel-syntax.el
@@ -208,6 +208,9 @@
           (format ":[^ ]* [^ ]+\\(%s\\)*" fuel-syntax--stack-effect-regex)
           "M[^:]*: [^ ]+ [^ ]+"))
 
+(defconst fuel-syntax--constructor-regex
+  "\\_<C: +\\(\\w+\\) +\\(\\w+\\)\\( .*\\)?$")
+
 
 ;;; Factor syntax table