diff --git a/packages/utils/src/assert.spec.ts b/packages/utils/src/assert.spec.ts
index 4b6374cfc0..d22b5c16cd 100644
--- a/packages/utils/src/assert.spec.ts
+++ b/packages/utils/src/assert.spec.ts
@@ -1,52 +1,54 @@
-import { assertDefined } from "./assert";
+import { assertDefinedAndNotNull } from "./assert";
 
 describe("assert", () => {
-  describe("assertDefined", () => {
+  describe("assertDefinedAndNotNull", () => {
     it("passes for simple values", () => {
       {
-        const value: number | undefined = 123;
-        assertDefined(value);
+        const value: number | undefined | null = 123;
+        assertDefinedAndNotNull(value);
         expect(value).toEqual(123);
       }
       {
-        const value: string | undefined = "abc";
-        assertDefined(value);
+        const value: string | undefined | null = "abc";
+        assertDefinedAndNotNull(value);
         expect(value).toEqual("abc");
       }
     });
 
     it("passes for falsy values", () => {
       {
-        const value: number | undefined = 0;
-        assertDefined(value);
+        const value: number | undefined | null = 0;
+        assertDefinedAndNotNull(value);
         expect(value).toEqual(0);
       }
       {
-        const value: string | undefined = "";
-        assertDefined(value);
+        const value: string | undefined | null = "";
+        assertDefinedAndNotNull(value);
         expect(value).toEqual("");
       }
-      {
-        const value: null | undefined = null;
-        assertDefined(value);
-        expect(value).toEqual(null);
-      }
     });
 
     it("throws for undefined values", () => {
       {
-        const value: number | undefined = undefined;
-        expect(() => assertDefined(value)).toThrowError("value is undefined");
+        const value: number | undefined | null = undefined;
+        expect(() => assertDefinedAndNotNull(value)).toThrowError("value is undefined or null");
       }
       {
-        let value: string | undefined;
-        expect(() => assertDefined(value)).toThrowError("value is undefined");
+        let value: string | undefined | null;
+        expect(() => assertDefinedAndNotNull(value)).toThrowError("value is undefined or null");
       }
     });
 
+    it("throws for null values", () => {
+      const value: number | undefined | null = null;
+      expect(() => assertDefinedAndNotNull(value)).toThrowError("value is undefined or null");
+    });
+
     it("throws with custom message", () => {
       const value: number | undefined = undefined;
-      expect(() => assertDefined(value, "Bug in the data source")).toThrowError("Bug in the data source");
+      expect(() => assertDefinedAndNotNull(value, "Bug in the data source")).toThrowError(
+        "Bug in the data source",
+      );
     });
   });
 });
diff --git a/packages/utils/src/assert.ts b/packages/utils/src/assert.ts
index 3c86b35378..14f37517ca 100644
--- a/packages/utils/src/assert.ts
+++ b/packages/utils/src/assert.ts
@@ -5,8 +5,8 @@ export function assert(condition: any, msg?: string): asserts condition {
   }
 }
 
-export function assertDefined<T>(value: T | undefined, msg?: string): asserts value is T {
-  if (value === undefined) {
-    throw new Error(msg || "value is undefined");
+export function assertDefinedAndNotNull<T>(value: T | undefined | null, msg?: string): asserts value is T {
+  if (value === undefined || value === null) {
+    throw new Error(msg ?? "value is undefined or null");
   }
 }
diff --git a/packages/utils/src/index.ts b/packages/utils/src/index.ts
index 391b2471c2..596d63db78 100644
--- a/packages/utils/src/index.ts
+++ b/packages/utils/src/index.ts
@@ -1,4 +1,4 @@
 export { arrayContentEquals } from "./arrays";
-export { assert, assertDefined } from "./assert";
+export { assert, assertDefinedAndNotNull } from "./assert";
 export { sleep } from "./sleep";
 export { isNonNullObject, isUint8Array } from "./typechecks";
diff --git a/packages/utils/types/assert.d.ts b/packages/utils/types/assert.d.ts
index 385fadf14f..65f3dfdb86 100644
--- a/packages/utils/types/assert.d.ts
+++ b/packages/utils/types/assert.d.ts
@@ -1,2 +1,5 @@
 export declare function assert(condition: any, msg?: string): asserts condition;
-export declare function assertDefined<T>(value: T | undefined, msg?: string): asserts value is T;
+export declare function assertDefinedAndNotNull<T>(
+  value: T | undefined | null,
+  msg?: string,
+): asserts value is T;
diff --git a/packages/utils/types/index.d.ts b/packages/utils/types/index.d.ts
index 391b2471c2..596d63db78 100644
--- a/packages/utils/types/index.d.ts
+++ b/packages/utils/types/index.d.ts
@@ -1,4 +1,4 @@
 export { arrayContentEquals } from "./arrays";
-export { assert, assertDefined } from "./assert";
+export { assert, assertDefinedAndNotNull } from "./assert";
 export { sleep } from "./sleep";
 export { isNonNullObject, isUint8Array } from "./typechecks";