diff --git a/common/content/completion.js b/common/content/completion.js
index 82180d24..1e0d436d 100644
--- a/common/content/completion.js
+++ b/common/content/completion.js
@@ -597,8 +597,12 @@ const CompletionContext = Class("CompletionContext", {
 
         if (!context.autoComplete && !context.tabPressed && context.editor)
             context.waitingForTab = true;
-        else if (completer)
-            return completer.apply(self || this, [context].concat(Array.slice(arguments, fork.length)));
+        else if (completer) {
+            let res = completer.apply(self || this, [context].concat(Array.slice(arguments, fork.length)));
+            if (res && !isArray(res) && !isArray(res.__proto__))
+                return [k for (k in res)];
+            return res;
+        }
         if (completer)
             return null;
         return context;
diff --git a/common/content/options.js b/common/content/options.js
index f9f0ad70..7d51d6a6 100644
--- a/common/content/options.js
+++ b/common/content/options.js
@@ -8,6 +8,8 @@
 
 /** @scope modules */
 
+let ValueError = Class("ValueError", Error);
+
 // do NOT create instances of this class yourself, use the helper method
 // options.add() instead
 /**
@@ -227,6 +229,8 @@ const Option = Class("Option", {
                 return this.invalidArgument(str || this.stringify(values), operator);
         }
         catch (e) {
+            if (!(e instanceof ValueError))
+                dactyl.reportError(e);
             return this.invalidArgument(str || this.stringify(values), operator) + ": " + e.message;
         }
 
@@ -563,7 +567,7 @@ const Option = Class("Option", {
     validIf: function (test, error) {
         if (test)
             return true;
-        throw Error(error);
+        throw ValueError(error);
     },
 
     // TODO: Run this by default?