diff --git a/misc/fuel/fuel-font-lock.el b/misc/fuel/fuel-font-lock.el
index 99a7c7b8fb..10561ded68 100644
--- a/misc/fuel/fuel-font-lock.el
+++ b/misc/fuel/fuel-font-lock.el
@@ -72,11 +72,21 @@
 
 ;;; Font lock:
 
+(defun fuel-font-lock--syntactic-face (state)
+  (cond ((nth 3 state) 'factor-font-lock-string)
+        ((char-equal (char-after (nth 8 state)) ?\ )
+         (save-excursion
+           (goto-char (nth 8 state))
+           (beginning-of-line)
+           (cond ((looking-at "USING: ") 'factor-font-lock-vocabulary-name)
+                 ((looking-at "\\(TUPLE\\|SYMBOLS\\|VARS\\): ")
+                  'factor-font-lock-symbol)
+                 (t 'default))))
+        (t 'factor-font-lock-comment)))
+
 (defconst fuel-font-lock--font-lock-keywords
   `((,fuel-syntax--stack-effect-regex . 'factor-font-lock-stack-effect)
-    (,fuel-syntax--parsing-words-regex . 'factor-font-lock-parsing-word)
     (,fuel-syntax--brace-words-regex 1 'factor-font-lock-parsing-word)
-    ("\\(P\\|SBUF\\)\"" 1 'factor-font-lock-parsing-word)
     (,fuel-syntax--vocab-ref-regexp  2 'factor-font-lock-vocabulary-name)
     (,fuel-syntax--declaration-words-regex . 'factor-font-lock-declaration)
     (,fuel-syntax--word-definition-regex 2 'factor-font-lock-word)
@@ -89,24 +99,26 @@
     (,fuel-syntax--type-definition-regex 2 'factor-font-lock-type-name)
     (,fuel-syntax--method-definition-regex (1 'factor-font-lock-type-name)
                                            (2 'factor-font-lock-word))
-    (,fuel-syntax--parent-type-regex 2 'factor-font-lock-type-name)
+    (,fuel-syntax--tuple-decl-regex 2 'factor-font-lock-type-name)
     (,fuel-syntax--constructor-regex . 'factor-font-lock-constructor)
     (,fuel-syntax--setter-regex . 'factor-font-lock-setter-word)
     (,fuel-syntax--getter-regex . 'factor-font-lock-getter-word)
     (,fuel-syntax--symbol-definition-regex 2 'factor-font-lock-symbol)
-    (,fuel-syntax--bad-string-regex . 'factor-font-lock-invalid-syntax)))
+    (,fuel-syntax--bad-string-regex . 'factor-font-lock-invalid-syntax)
+    ("\\(P\\|SBUF\\)\"" 1 'factor-font-lock-parsing-word)
+    (,fuel-syntax--parsing-words-regex . 'factor-font-lock-parsing-word)))
 
 (defun fuel-font-lock--font-lock-setup (&optional keywords no-syntax)
   (set (make-local-variable 'comment-start) "! ")
   (set (make-local-variable 'parse-sexp-lookup-properties) t)
-  (set (make-local-variable 'font-lock-comment-face) 'factor-font-lock-comment)
-  (set (make-local-variable 'font-lock-string-face) 'factor-font-lock-string)
   (set (make-local-variable 'font-lock-defaults)
        `(,(or keywords 'fuel-font-lock--font-lock-keywords)
          nil nil nil nil
          ,@(if no-syntax nil
              (list (cons 'font-lock-syntactic-keywords
-                         fuel-syntax--syntactic-keywords))))))
+                         fuel-syntax--syntactic-keywords)
+                   (cons 'font-lock-syntactic-face-function
+                         'fuel-font-lock--syntactic-face))))))
 
 
 ;;; Fontify strings as Factor code:
diff --git a/misc/fuel/fuel-listener.el b/misc/fuel/fuel-listener.el
index 66034225f1..f1be6a5607 100644
--- a/misc/fuel/fuel-listener.el
+++ b/misc/fuel/fuel-listener.el
@@ -68,7 +68,8 @@ buffer."
       (setq fuel-listener--buffer (current-buffer)))))
 
 (defun fuel-listener--start-process ()
-  (let ((factor (expand-file-name fuel-listener-factor-binary))
+  (let ((factor (locate-file (expand-file-name fuel-listener-factor-binary)
+                             '("") exec-suffixes))
         (image (expand-file-name fuel-listener-factor-image))
         (comint-redirect-perform-sanity-check nil))
     (unless (file-executable-p factor)
@@ -132,8 +133,7 @@ buffer."
 
 (defun fuel-listener--setup-completion ()
   (setq fuel-syntax--current-vocab-function 'fuel-listener--current-vocab)
-  (setq fuel-syntax--usings-function 'fuel-listener--usings)
-  (set-syntax-table fuel-syntax--syntax-table))
+  (setq fuel-syntax--usings-function 'fuel-listener--usings))
 
 
 ;;; Stack mode support
@@ -160,7 +160,6 @@ buffer."
   (set (make-local-variable 'comint-prompt-regexp) fuel-con--prompt-regex)
   (set (make-local-variable 'comint-use-prompt-regexp) t)
   (set (make-local-variable 'comint-prompt-read-only) t)
-  (set-syntax-table fuel-syntax--syntax-table)
   (fuel-listener--setup-completion)
   (fuel-listener--setup-stack-mode))
 
diff --git a/misc/fuel/fuel-syntax.el b/misc/fuel/fuel-syntax.el
index b74b0afc11..5aaaa33964 100644
--- a/misc/fuel/fuel-syntax.el
+++ b/misc/fuel/fuel-syntax.el
@@ -87,14 +87,22 @@
 (defconst fuel-syntax--integer-regex
   "\\_<-?[0-9]+\\_>")
 
-(defconst fuel-syntax--ratio-regex
-  "\\_<-?\\([0-9]+\\+\\)?[0-9]+/-?[0-9]+\\_>")
+(defconst fuel-syntax--raw-float-regex
+  "[0-9]*\\.[0-9]*\\([eE][+-]?[0-9]+\\)?")
 
 (defconst fuel-syntax--float-regex
-  "\\_<-?[0-9]+\\.[0-9]*\\([eE][+-]?[0-9]+\\)?\\_>")
+  (format "\\_<-?%s\\_>" fuel-syntax--raw-float-regex))
+
+(defconst fuel-syntax--number-regex
+  (format "\\([0-9]+\\|%s\\)" fuel-syntax--raw-float-regex))
+
+(defconst fuel-syntax--ratio-regex
+  (format "\\_<[+-]?%s/-?%s\\_>"
+          fuel-syntax--number-regex
+          fuel-syntax--number-regex))
 
 (defconst fuel-syntax--bad-string-regex
-  "\"\\([^\"]\\|\\\\\"\\)*\n")
+  "\\_<\"[^>]\\([^\"\n]\\|\\\\\"\\)*\n")
 
 (defconst fuel-syntax--word-definition-regex
   (fuel-syntax--second-word-regex
@@ -114,8 +122,8 @@
 (defconst fuel-syntax--type-definition-regex
   (fuel-syntax--second-word-regex '("MIXIN:" "TUPLE:" "SINGLETON:" "UNION:")))
 
-(defconst fuel-syntax--parent-type-regex
-  "^\\(TUPLE\\|PREDICTE\\): +[^ ]+ +< +\\([^ ]+\\)")
+(defconst fuel-syntax--tuple-decl-regex
+  "^TUPLE: +\\([^ \n]+\\) +< +\\([^ \n]+\\)\\_>")
 
 (defconst fuel-syntax--constructor-regex "<[^ >]+>")
 
@@ -125,7 +133,8 @@
 (defconst fuel-syntax--symbol-definition-regex
   (fuel-syntax--second-word-regex '("SYMBOL:" "VAR:")))
 
-(defconst fuel-syntax--stack-effect-regex " ( .* )")
+(defconst fuel-syntax--stack-effect-regex
+  "\\( ( .* )\\)\\|\\( (( .* ))\\)")
 
 (defconst fuel-syntax--using-lines-regex "^USING: +\\([^;]+\\);")
 
@@ -220,13 +229,20 @@
     table))
 
 (defconst fuel-syntax--syntactic-keywords
-  `(;; Comments:
+  `(;; CHARs:
+    ("CHAR: \\(.\\)\\( \\|$\\)" (1 "w"))
+    ;; Comments:
     ("\\_<\\(#?!\\) .*\\(\n\\|$\\)" (1 "<") (2 ">"))
     ("\\_<\\(#?!\\)\\(\n\\|$\\)" (1 "<") (2 ">"))
-    ;; CHARs:
-    ("CHAR: \\(.\\)\\( \\|$\\)" (1 "w"))
     ;; Strings
-    ("\\(\"\\)\\([^\n\r\f\\\"]\\|\\\\\"?\\)*\\(\"\\)" (1 "\"") (3 "\""))
+    ("\\_<\\(\"\\)\\([^\n\r\f\\\"]\\|\\\\\"\\)*\\(\"\\)\\_>" (1 "\"") (3 "\""))
+    ("\\_<<\\(\"\\)\\_>" (1 "\""))
+    ("\\_<\\(\"\\)>\\_>" (1 "\""))
+    ;; Multiline constructs
+    ("\\_<USING:\\( \\)" (1 "<b"))
+    ("\\_<TUPLE: +\\w+? +< +\\w+? *\\( \\)" (1 "<b"))
+    ("\\_<\\(TUPLE\\|SYMBOLS\\|VARS\\): +\\w+? *\\( \\)\\([^<]\\|\\_>\\)" (2 "<b"))
+    ("\\(\n\\| \\);\\_>" (1 ">b"))
     ;; Let and lambda:
     ("\\_<\\(!(\\) .* \\()\\)" (1 "<") (2 ">"))
     ("\\(\\[\\)\\(let\\|wlet\\|let\\*\\)\\( \\|$\\)" (1 "(]"))