diff --git a/src/v1/function-builder.ts b/src/v1/function-builder.ts
index 0f813ec96..c7e5daa3e 100644
--- a/src/v1/function-builder.ts
+++ b/src/v1/function-builder.ts
@@ -53,7 +53,7 @@ import * as testLab from "./providers/testLab";
  */
 function assertRuntimeOptionsValid(runtimeOptions: RuntimeOptions): boolean {
   const mem = runtimeOptions.memory;
-  if (mem && !(mem instanceof ResetValue) && !VALID_MEMORY_OPTIONS.includes(mem)) {
+  if (mem && typeof mem !== "object" && !VALID_MEMORY_OPTIONS.includes(mem)) {
     throw new Error(
       `The only valid memory allocation values are: ${VALID_MEMORY_OPTIONS.join(", ")}`
     );
diff --git a/src/v1/function-configuration.ts b/src/v1/function-configuration.ts
index cbaef9803..bb5e07f8f 100644
--- a/src/v1/function-configuration.ts
+++ b/src/v1/function-configuration.ts
@@ -178,11 +178,11 @@ export interface RuntimeOptions {
   /**
    * Amount of memory to allocate to the function.
    */
-  memory?: typeof VALID_MEMORY_OPTIONS[number] | ResetValue;
+  memory?: typeof VALID_MEMORY_OPTIONS[number] | Expression<number> | ResetValue;
   /**
    * Timeout for the function in seconds, possible values are 0 to 540.
    */
-  timeoutSeconds?: number | ResetValue;
+  timeoutSeconds?: number | Expression<number> | ResetValue;
 
   /**
    * Min number of actual instances to be running at a given time.
@@ -191,12 +191,12 @@ export interface RuntimeOptions {
    * Instances will be billed for memory allocation and 10% of CPU allocation
    * while idle.
    */
-  minInstances?: number | ResetValue;
+  minInstances?: number | Expression<number> | ResetValue;
 
   /**
    * Max number of actual instances allowed to be running in parallel.
    */
-  maxInstances?: number | ResetValue;
+  maxInstances?: number | Expression<number> | ResetValue;
 
   /**
    * Connect cloud function to specified VPC connector.