diff --git a/types/hast/hast-tests.ts b/types/hast/hast-tests.ts
index 68699d6dd3..595c642818 100644
--- a/types/hast/hast-tests.ts
+++ b/types/hast/hast-tests.ts
@@ -73,6 +73,9 @@ const properties: Properties = {
     propertyName2: ['propertyValue2', 'propertyValue3'],
     propertyName3: true,
     propertyName4: 47,
+    propertyName5: [4, "4"],
+    propertyName6: null,
+    propertyName7: undefined
 };
 
 function getElement(): Element {
diff --git a/types/hast/index.d.ts b/types/hast/index.d.ts
index 85aa548b3b..dd08f9da82 100644
--- a/types/hast/index.d.ts
+++ b/types/hast/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/syntax-tree/hast
 // Definitions by: lukeggchapman <https://github.com/lukeggchapman>
 //                 Junyoung Choi <https://github.com/rokt33r>
+//                 Christian Murphy <https://github.com/ChristianMurphy>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 3.0
 
@@ -72,7 +73,7 @@ export interface Element extends Parent {
  * Represents information associated with an element.
  */
 export interface Properties {
-    [PropertyName: string]: any;
+    [PropertyName: string]: boolean | number | string | null | undefined | Array<string | number>;
 }
 
 /**