diff --git a/extract-data.js b/extract-data.js
index 6fec0e7..657955f 100644
--- a/extract-data.js
+++ b/extract-data.js
@@ -17,6 +17,7 @@ const idlreducer = (impldata, name) => (idlacc, member) => {
   if (member.name) {
     const browserdata = impldata.array.find(d => d.id === name + "#" + member.name);
     if (!browserdata) {
+      idlacc[member.name] = null;
       return idlacc;
     }
     idlacc[member.name] = Object.keys(browserdata)
diff --git a/index.html b/index.html
index daeb487..ccb1f68 100644
--- a/index.html
+++ b/index.html
@@ -10,6 +10,7 @@
       th[scope="row"] + td { border-right: 1px black solid;}
       td { border-right: 1px #aaa solid;}
       tr td:first-child { border-right: 1px black solid;}
+      .unknown { background-color: #eee;}
       .yes { background-color: #eFe;}
       .no { background-color: #Fee;}
       .yes2 { background-color: #cFc;}
diff --git a/script.js b/script.js
index 84e5bcd..ab8edae 100644
--- a/script.js
+++ b/script.js
@@ -29,18 +29,22 @@ fetch(shortname + ".json")
 
         const nameSpan = document.createElement("span");
         const scoreSpan = document.createElement("span");
-        nameSpan.textContent = member + " ";
-        scoreSpan.textContent = Object.keys(d[name][member]).length + "/4";
         scoreSpan.className = "score";
+        nameSpan.textContent = member + " ";
+        if (!d[name][member]) {
+          scoreSpan.textContent = "?/4";
+          memberTd.className = "unknown";
+        } else {
+          scoreSpan.textContent = Object.keys(d[name][member]).length + "/4";
+          memberTd.className = Object.keys(d[name][member]).length >= 2 ? "yes" + Object.keys(d[name][member]).length : "no" + (4 - Object.keys(d[name][member]).length);
+          markupBrowserSupport(chromeTd, d[name][member].chrome);
+          markupBrowserSupport(edgeTd, d[name][member].edge);
+          markupBrowserSupport(firefoxTd, d[name][member].firefox);
+          markupBrowserSupport(safariTd, d[name][member].safari);
+        }
+
         memberTd.appendChild(nameSpan);
         memberTd.appendChild(scoreSpan);
-
-        memberTd.className = Object.keys(d[name][member]).length >= 2 ? "yes" + Object.keys(d[name][member]).length : "no" + (4 - Object.keys(d[name][member]).length);
-        markupBrowserSupport(chromeTd, d[name][member].chrome);
-        markupBrowserSupport(edgeTd, d[name][member].edge);
-        markupBrowserSupport(firefoxTd, d[name][member].firefox);
-        markupBrowserSupport(safariTd, d[name][member].safari);
-
         container.appendChild(memberTd);
         container.appendChild(chromeTd);
         container.appendChild(edgeTd);