diff --git a/client/src/utils/pushOrSet.ts b/client/src/utils/pushOrSet.ts
index de24c991c44..b38886bd86b 100644
--- a/client/src/utils/pushOrSet.ts
+++ b/client/src/utils/pushOrSet.ts
@@ -1,6 +1,12 @@
-export function pushOrSet(object: { [index: string | number]: any[] }, key: string | number, value: any) {
+/**
+ * Pushes a value to an array in an object, if the array exists. Else creates a new array containing value.
+ * @param object Object which contains array
+ * @param key Key which array is in
+ * @param value Value to push
+ */
+export function pushOrSet<T, K extends string | number | symbol>(object: { [key in K]: Array<T> }, key: K, value: T) {
     if (key in object) {
-        object[key].push(value);
+        object[key]!.push(value);
     } else {
         object[key] = [value];
     }