diff --git a/packages/test/src/test-workflows.ts b/packages/test/src/test-workflows.ts
index 55220d9ee..8baf6d82e 100644
--- a/packages/test/src/test-workflows.ts
+++ b/packages/test/src/test-workflows.ts
@@ -76,13 +76,13 @@ function makeActivation(
   };
 }
 
-function makeUnblockTimer(timerId: string, timestamp: number = Date.now()): iface.coresdk.IWFActivation {
-  return makeActivation(timestamp, makeUnblockTimerJob(timerId));
+function makeFireTimer(timerId: string, timestamp: number = Date.now()): iface.coresdk.IWFActivation {
+  return makeActivation(timestamp, makeFireTimerJob(timerId));
 }
 
-function makeUnblockTimerJob(timerId: string): iface.coresdk.IWFActivationJob {
+function makeFireTimerJob(timerId: string): iface.coresdk.IWFActivationJob {
   return {
-    timerFired: { timerId },
+    fireTimer: { timerId },
   };
 }
 
@@ -214,7 +214,7 @@ test('set-timeout', async (t) => {
     compareCompletion(t, req, makeSuccess([makeStartTimerCommand({ timerId: '0', startToFireTimeout: msToTs(100) })]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [['slept']]);
@@ -227,7 +227,7 @@ test('set-timeout-after-microtasks', async (t) => {
     compareCompletion(t, req, makeSuccess([makeStartTimerCommand({ timerId: '0', startToFireTimeout: msToTs(100) })]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [['slept']]);
@@ -261,7 +261,7 @@ test('tasks-and-microtasks', async (t) => {
     compareCompletion(t, req, makeSuccess([makeStartTimerCommand({ timerId: '0', startToFireTimeout: msToTs(0) })]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [['script start'], ['script end'], ['promise1'], ['promise2'], ['setTimeout']]);
@@ -281,7 +281,7 @@ test('trailing-timer', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeActivation(undefined, makeUnblockTimerJob('0'), makeUnblockTimerJob('1')));
+    const req = await activate(t, makeActivation(undefined, makeFireTimerJob('0'), makeFireTimerJob('1')));
     // Note that the trailing timer does not get scheduled since the workflow completes
     // after the first timer is triggered causing the second one to be dropped.
     compareCompletion(t, req, makeSuccess([makeCompleteWorkflowExecution(defaultDataConverter.toPayload('first'))]));
@@ -303,7 +303,7 @@ test('promise-race', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeActivation(undefined, makeUnblockTimerJob('0'), makeUnblockTimerJob('1')));
+    const req = await activate(t, makeActivation(undefined, makeFireTimerJob('0'), makeFireTimerJob('1')));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [[1], [1], [1], [1], [20], ['wow']]);
@@ -323,11 +323,11 @@ test('race', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess([]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('1'));
+    const req = await activate(t, makeFireTimer('1'));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [[1], [2], [3]]);
@@ -340,7 +340,7 @@ test('importer', async (t) => {
     compareCompletion(t, req, makeSuccess([makeStartTimerCommand({ timerId: '0', startToFireTimeout: msToTs(10) })]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [['slept']]);
@@ -405,7 +405,7 @@ test('simple-query', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess());
   }
   {
@@ -450,7 +450,7 @@ test('cancel-workflow', async (t) => {
     compareCompletion(t, req, makeSuccess([]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('2'));
+    const req = await activate(t, makeFireTimer('2'));
     compareCompletion(t, req, makeSuccess([makeCompleteWorkflowExecution(defaultDataConverter.toPayload({ url }))]));
   }
   t.deepEqual(logs, [['Workflow cancelled'], ['Workflow cancelled'], ['Workflow cancelled']]);
@@ -507,7 +507,7 @@ test('cancellation-scopes', async (t) => {
     compareCompletion(t, req, makeSuccess([makeStartTimerCommand({ timerId: '0', startToFireTimeout: msToTs(3) })]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(
       t,
       req,
@@ -519,7 +519,7 @@ test('cancellation-scopes', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeUnblockTimer('2'));
+    const req = await activate(t, makeFireTimer('2'));
     compareCompletion(t, req, makeSuccess([makeStartTimerCommand({ timerId: '3', startToFireTimeout: msToTs(3) })]));
   }
   {
@@ -549,11 +549,11 @@ test('child-and-shield', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess([]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('1'));
+    const req = await activate(t, makeFireTimer('1'));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [['Exception was propagated 👍'], ['Slept in shield 👍']]);
@@ -573,7 +573,7 @@ test('partial-shield', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeUnblockTimer('1'));
+    const req = await activate(t, makeFireTimer('1'));
     compareCompletion(t, req, makeSuccess([makeStartTimerCommand({ timerId: '2', startToFireTimeout: msToTs(2) })]));
   }
   {
@@ -588,11 +588,11 @@ test('partial-shield', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess([makeStartTimerCommand({ timerId: '4', startToFireTimeout: msToTs(1) })]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('3'));
+    const req = await activate(t, makeFireTimer('3'));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [['Workflow cancelled']]);
@@ -612,11 +612,11 @@ test('shield-in-shield', async (t) => {
     );
   }
   {
-    const req = await activate(t, makeUnblockTimer('1'));
+    const req = await activate(t, makeFireTimer('1'));
     compareCompletion(t, req, makeSuccess([]));
   }
   {
-    const req = await activate(t, makeUnblockTimer('0'));
+    const req = await activate(t, makeFireTimer('0'));
     compareCompletion(t, req, makeSuccess());
   }
   t.deepEqual(logs, [
diff --git a/packages/worker/native/sdk-core b/packages/worker/native/sdk-core
index ac936a9c1..ec360a5c9 160000
--- a/packages/worker/native/sdk-core
+++ b/packages/worker/native/sdk-core
@@ -1 +1 @@
-Subproject commit ac936a9c17acf15102c24a823a63629271917f1a
+Subproject commit ec360a5c9f8ef2b274c545c04e4f9b66a6d1914f
diff --git a/packages/workflow/src/internals.ts b/packages/workflow/src/internals.ts
index 3717c448a..299a962e8 100644
--- a/packages/workflow/src/internals.ts
+++ b/packages/workflow/src/internals.ts
@@ -146,7 +146,7 @@ function timerIdToSeq(timerId: string | undefined | null) {
 }
 
 export class Activator implements WorkflowTaskHandler {
-  public startWorkflow(activation: iface.coresdk.IStartWorkflowTaskAttributes): void {
+  public startWorkflow(activation: iface.coresdk.IStartWorkflow): void {
     if (state.workflow === undefined) {
       throw new Error('state.workflow is not defined');
     }
@@ -163,17 +163,17 @@ export class Activator implements WorkflowTaskHandler {
     }
   }
 
-  public cancelWorkflow(_activation: iface.coresdk.ICancelWorkflowTaskAttributes): void {
+  public cancelWorkflow(_activation: iface.coresdk.ICancelWorkflow): void {
     state.cancelled = true;
     rootScopeCancel(new CancellationError('Workflow cancelled'));
   }
 
-  public timerFired(activation: iface.coresdk.ITimerFiredTaskAttributes): void {
+  public fireTimer(activation: iface.coresdk.IFireTimer): void {
     const { resolve } = consumeCompletion(timerIdToSeq(activation.timerId));
     resolve(undefined);
   }
 
-  public timerCanceled(activation: iface.coresdk.ITimerCanceledTaskAttributes): void {
+  public cancelTimer(activation: iface.coresdk.ICancelTimer): void {
     const { scope } = consumeCompletion(timerIdToSeq(activation.timerId));
     try {
       scope.cancel(new CancellationError('Timer cancelled'));
@@ -182,7 +182,7 @@ export class Activator implements WorkflowTaskHandler {
     }
   }
 
-  public queryWorkflow(job: iface.coresdk.IQueryWorkflowJob): void {
+  public queryWorkflow(job: iface.coresdk.IQueryWorkflow): void {
     if (state.workflow === undefined) {
       throw new Error('state.workflow is not defined');
     }
@@ -208,7 +208,7 @@ export class Activator implements WorkflowTaskHandler {
     }
   }
 
-  public randomSeedUpdated(_activation: iface.coresdk.IRandomSeedUpdatedAttributes): void {
+  public updateRandomSeed(_activation: iface.coresdk.IUpdateRandomSeed): void {
     throw new Error('Not implemented');
   }
 }
@@ -224,20 +224,20 @@ export function activate(encodedActivation: Uint8Array, jobIndex: number): boole
   if (state.activator === undefined) {
     throw new Error('state.activator is not defined');
   }
-  if (job.attributes === undefined) {
-    throw new Error('Expected job.attributes to be defined');
+  if (job.variant === undefined) {
+    throw new Error('Expected job.variant to be defined');
   }
-  const attrs = job[job.attributes];
-  if (!attrs) {
-    throw new Error(`Expected job.${job.attributes} to be set`);
+  const variant = job[job.variant];
+  if (!variant) {
+    throw new Error(`Expected job.${job.variant} to be set`);
   }
   // The only job that can be executed on a completed workflow is a query.
   // We might get other jobs after completion for instance when a single
   // activation contains multiple jobs and the first one completes the workflow.
-  if (state.completed && job.attributes !== 'queryWorkflow') {
+  if (state.completed && job.variant !== 'queryWorkflow') {
     return false;
   }
-  state.activator[job.attributes](attrs);
+  state.activator[job.variant](variant);
   return true;
 }