diff --git a/types/vega/index.d.ts b/types/vega/index.d.ts
index b10bf40cac..da7b0fee32 100644
--- a/types/vega/index.d.ts
+++ b/types/vega/index.d.ts
@@ -406,7 +406,7 @@ declare namespace vg {
     description?: string;
     from?: Mark.From;
     key?: string;
-    delay?: ValueRef;
+    delay?: ValueRefs;
     /**
     * "linear-in" | "linear-out" | "linear-in-out" | "linear-out-in" | "quad-in" | "quad-out" | "quad-in-out" |
     * "quad-out-in" | "cubic-in" | "cubic-out" | "cubic-in-out" | "cubic-out-in" | "sin-in" | "sin-out" | "sin-in-out" |
@@ -465,54 +465,54 @@ declare namespace vg {
     // TODO docs
 
     // -- Shared visual properties
-    x?: ValueRef;
-    x2?: ValueRef;
-    width?: ValueRef;
-    y?: ValueRef;
-    y2?: ValueRef;
-    height?: ValueRef;
-    opacity?: ValueRef;
-    fill?: ValueRef;
-    fillOpacity?: ValueRef;
-    stroke?: ValueRef;
-    strokeWidth?: ValueRef;
-    strokeOpacity?: ValueRef;
-    strokeDash?: ValueRef;
-    strokeDashOffset?: ValueRef;
+    x?: ValueRefs;
+    x2?: ValueRefs;
+    width?: ValueRefs;
+    y?: ValueRefs;
+    y2?: ValueRefs;
+    height?: ValueRefs;
+    opacity?: ValueRefs;
+    fill?: ValueRefs;
+    fillOpacity?: ValueRefs;
+    stroke?: ValueRefs;
+    strokeWidth?: ValueRefs;
+    strokeOpacity?: ValueRefs;
+    strokeDash?: ValueRefs;
+    strokeDashOffset?: ValueRefs;
 
     // -- symbol
-    size?: ValueRef;
-    shape?: ValueRef;
+    size?: ValueRefs;
+    shape?: ValueRefs;
 
     // -- path
-    path?: ValueRef;
+    path?: ValueRefs;
 
     // -- arc
-    innerRadius?: ValueRef;
-    outerRadius?: ValueRef;
-    startAngle?: ValueRef;
-    endAngle?: ValueRef;
+    innerRadius?: ValueRefs;
+    outerRadius?: ValueRefs;
+    startAngle?: ValueRefs;
+    endAngle?: ValueRefs;
 
     // -- area / line
-    interpolate?: ValueRef;
-    tension?: ValueRef;
+    interpolate?: ValueRefs;
+    tension?: ValueRefs;
 
     // -- image / text
-    align?: ValueRef;
-    baseline?: ValueRef;
+    align?: ValueRefs;
+    baseline?: ValueRefs;
 
     // -- image
-    url?: ValueRef;
+    url?: ValueRefs;
 
     // -- text
-    text?: ValueRef;
-    dx?: ValueRef;
-    dy?: ValueRef;
-    angle?: ValueRef;
-    font?: ValueRef;
-    fontSize?: ValueRef;
-    fontWeight?: ValueRef;
-    fontStyle?: ValueRef;
+    text?: ValueRefs;
+    dx?: ValueRefs;
+    dy?: ValueRefs;
+    angle?: ValueRefs;
+    font?: ValueRefs;
+    fontSize?: ValueRefs;
+    fontWeight?: ValueRefs;
+    fontStyle?: ValueRefs;
   }
 
   export interface ValueRef {
@@ -524,8 +524,11 @@ declare namespace vg {
     mult?: number;
     offset?: number;
     band?: boolean;
+    test?: string;
   }
 
+  export type ValueRefs = ValueRef | ValueRef[];
+
   export var parse: Parse;
   export namespace scene {
     export function item(mark: Node): Node;
diff --git a/types/vega/vega-tests.ts b/types/vega/vega-tests.ts
index 2e66d478f3..5baeaee024 100644
--- a/types/vega/vega-tests.ts
+++ b/types/vega/vega-tests.ts
@@ -1957,6 +1957,13 @@ specs[20] = {
   ]
 }
 
+const hoverFill21: Vega.ValueRefs = [{
+  "test": "datum.value < 30",
+  "value": "#f00"
+}, {
+  "value": "#f55"
+}];
+
 specs[21] = {
   "name": "wordcloud",
   "width": 400,
@@ -2006,10 +2013,15 @@ specs[21] = {
           "text": { "field": "data.text" }
         },
         "update": {
-          "fill": { "value": "steelblue" }
+          "fill": [{
+            "test": "datum.value < 30",
+            "value": "steelblue"
+          }, {
+            "value": "blue"
+          }]
         },
         "hover": {
-          "fill": { "value": "#f00" }
+          "fill": hoverFill21
         }
       }
     }
@@ -2020,4 +2032,4 @@ specs.forEach(spec => {
   vg.parse.spec(spec, chart => {
   chart({el:"#vis"}).update();
   });
-});
\ No newline at end of file
+});