diff --git a/lib/convert-worker.js b/lib/convert-worker.js
index a2a38ac..069d369 100644
--- a/lib/convert-worker.js
+++ b/lib/convert-worker.js
@@ -543,6 +543,12 @@ function fixHyphens(xml) {
   xml = xml.replace(/(\w+)[ -]year[ -]old(s?)(?!\w)/g, "$1-year-old$2");
   xml = xml.replace(/(\w+) or (\w+)-year-old/g, "$1- or $2-year-old");
 
+  // Compound numbers must be hyphenated.
+  xml = xml.replace(
+    /(?<!\w)(twenty|thirty|fourty|fifty|sixty|seventy|eighty|ninety) (one|two|three|four|five|six|seven|eight|nine)/ig,
+    "$1-$2"
+  );
+
   // These are consistently missing hyphens.
   xml = xml.replace(/self destruct/g, "self-destruct");
   xml = xml.replace(/life threatening/g, "life-threatening");
diff --git a/lib/substitutions.json b/lib/substitutions.json
index e5dcbc8..9ea2728 100644
--- a/lib/substitutions.json
+++ b/lib/substitutions.json
@@ -787,10 +787,6 @@
       "before": "Walk or-",
       "after": "Walk or—"
     },
-    {
-      "before": "twenty six years",
-      "after": "twenty-six years"
-    },
     {
       "before": "<em>here?  Now?</em>",
       "after": "<em>here</em>?  <em>Now</em>?"
@@ -1886,7 +1882,7 @@
       "after": "my ‘candy’</em>"
     },
     {
-      "before": "Thirty Nine point",
+      "before": "Thirty-Nine point",
       "after": "Thirty-nine point"
     },
     {
@@ -3516,6 +3512,10 @@
     {
       "before": "a burst of alarm</em>.",
       "after": "a burst of alarm.</em>"
+    },
+    {
+      "before": "Up from Eighty-three point four percent",
+      "after": "Up from eighty-three point four percent"
     }
   ],
   "https://parahumans.wordpress.com/2013/07/23/sting-26-3/": [