diff --git a/types/slate/index.d.ts b/types/slate/index.d.ts
index ac58361ff8..bb35c6483f 100644
--- a/types/slate/index.d.ts
+++ b/types/slate/index.d.ts
@@ -327,7 +327,7 @@ export class Text extends Immutable.Record({}) {
     getFirstText(): Text;
     getLastText(): Text;
     getText(): string;
-    getMarksBetweenOffset(
+    getMarksBetweenOffsets(
         startOffset: number,
         endOffset: number
     ): Immutable.Set<Mark>;
@@ -362,7 +362,7 @@ export interface LeafProperties {
 }
 
 export interface LeafJSON {
-    marks?: Mark[];
+    marks?: MarkJSON[];
     text?: string;
 }
 
diff --git a/types/slate/slate-tests.ts b/types/slate/slate-tests.ts
index eb07649cba..344d4da3ee 100644
--- a/types/slate/slate-tests.ts
+++ b/types/slate/slate-tests.ts
@@ -13,7 +13,10 @@ const node: BlockJSON = {
 			leaves: [
 				{
 					text: "example",
-					marks: []
+					marks: [{
+                        data: { testData: "data"},
+                        type: "mark"
+                    }]
 				}
 			]
 		}