diff --git a/packages/server/src/sdk/app/automations/crud.ts b/packages/server/src/sdk/app/automations/crud.ts
index 90fe6c16c4..7a2f4c12d0 100644
--- a/packages/server/src/sdk/app/automations/crud.ts
+++ b/packages/server/src/sdk/app/automations/crud.ts
@@ -11,7 +11,7 @@ import {
 import { definitions } from "../../../automations/triggerInfo"
 import automations from "."
 
-interface PersistedAutomation extends Automation {
+type PersistedAutomation = Automation & {
   _id: string
   _rev: string
 }
@@ -125,6 +125,9 @@ export async function update(automation: Automation) {
   const db = getDb()
 
   const oldAutomation = await db.get<Automation>(automation._id)
+
+  guardInvalidUpdatesAndThrow(automation, oldAutomation)
+
   automation = cleanAutomationInputs(automation)
   automation = await checkForWebhooks({
     oldAuto: oldAutomation,
@@ -251,3 +254,30 @@ async function checkForWebhooks({ oldAuto, newAuto }: any) {
   }
   return newAuto
 }
+function guardInvalidUpdatesAndThrow(
+  automation: Automation,
+  oldAutomation: Automation
+) {
+  const stepDefinitions = [
+    automation.definition.trigger,
+    ...automation.definition.steps,
+  ]
+  const oldStepDefinitions = [
+    oldAutomation.definition.trigger,
+    ...oldAutomation.definition.steps,
+  ]
+  for (const step of stepDefinitions) {
+    const readonlyFields = Object.keys(
+      step.schema.inputs.properties || {}
+    ).filter(k => step.schema.inputs.properties[k].readonly)
+    readonlyFields.forEach(readonlyField => {
+      const oldStep = oldStepDefinitions.find(i => i.id === step.id)
+      if (step.inputs[readonlyField] !== oldStep?.inputs[readonlyField]) {
+        throw new HTTPError(
+          `Field ${readonlyField} is readonly and it cannot be modified`,
+          400
+        )
+      }
+    })
+  }
+}
diff --git a/packages/server/src/sdk/app/automations/tests/index.spec.ts b/packages/server/src/sdk/app/automations/tests/index.spec.ts
new file mode 100644
index 0000000000..295ab690d1
--- /dev/null
+++ b/packages/server/src/sdk/app/automations/tests/index.spec.ts
@@ -0,0 +1,54 @@
+import _ from "lodash/fp"
+import { Automation } from "@budibase/types"
+import automationSdk from "../"
+import { structures } from "../../../../api/routes/tests/utilities"
+import TestConfiguration from "../../../../tests/utilities/TestConfiguration"
+
+describe("automation sdk", () => {
+  const config = new TestConfiguration()
+
+  beforeAll(async () => {
+    await config.init()
+  })
+
+  describe("update", () => {
+    it("can update input fields", async () => {
+      await config.doInContext(config.getAppId(), async () => {
+        const automation: Automation = structures.newAutomation()
+        const keyToUse = _.sample(
+          Object.keys(automation.definition.trigger.inputs)
+        )!
+        automation.definition.trigger.inputs[keyToUse] = "anyValue"
+
+        const response = await automationSdk.create(automation)
+
+        const update = { ...response }
+        update.definition.trigger.inputs[keyToUse] = "anyUpdatedValue"
+        const result = await automationSdk.update(update)
+        expect(result.definition.trigger.inputs[keyToUse]).toEqual(
+          "anyUpdatedValue"
+        )
+      })
+    })
+
+    it("cannot update readonly fields", async () => {
+      await config.doInContext(config.getAppId(), async () => {
+        const automation: Automation = { ...structures.newAutomation() }
+        automation.definition.trigger.schema.inputs.properties[
+          "readonlyProperty"
+        ] = {
+          readonly: true,
+        }
+        automation.definition.trigger.inputs["readonlyProperty"] = "anyValue"
+
+        const response = await automationSdk.create(automation)
+
+        const update = { ...response }
+        update.definition.trigger.inputs["readonlyProperty"] = "anyUpdatedValue"
+        await expect(automationSdk.update(update)).rejects.toThrow(
+          "Field readonlyProperty is readonly and it cannot be modified"
+        )
+      })
+    })
+  })
+})