diff --git a/apps/sim/blocks/blocks/outlook.test.ts b/apps/sim/blocks/blocks/outlook.test.ts
index cd60240b048..c8b36c5ad46 100644
--- a/apps/sim/blocks/blocks/outlook.test.ts
+++ b/apps/sim/blocks/blocks/outlook.test.ts
@@ -5,6 +5,12 @@ import { describe, expect, it } from 'vitest'
 import { tools as toolRegistry } from '@/tools/registry'
 import { OutlookBlock } from './outlook'
 
+/**
+ * Uses the real tool registry: these assertions are about tool registration and
+ * params, which the global `@/tools/registry` mock in vitest.setup.ts empties.
+ */
+vi.unmock('@/tools/registry')
+
 const block = OutlookBlock
 
 /** Every calendar operation exposed by the block's operation dropdown. */
diff --git a/apps/sim/lib/workflows/search-replace/indexer.test.ts b/apps/sim/lib/workflows/search-replace/indexer.test.ts
index 2fe792b2073..e970b80c787 100644
--- a/apps/sim/lib/workflows/search-replace/indexer.test.ts
+++ b/apps/sim/lib/workflows/search-replace/indexer.test.ts
@@ -10,6 +10,17 @@ import {
 } from '@/lib/workflows/search-replace/search-replace.fixtures'
 import { WORKFLOW_SEARCH_SUBFLOW_FIELD_IDS } from '@/lib/workflows/search-replace/subflow-fields'
 
+/**
+ * Uses the real tool registry. Nothing here imports it directly — the dependency
+ * is transitive: the search-replace planner resolves tool input params through
+ * real subblock configs, so the global `@/tools/registry` mock in
+ * vitest.setup.ts empties the data these assertions read.
+ *
+ * Not a no-op, despite the lack of a direct import. Dropping this opt-out fails
+ * 8 tests across this file and its sibling suite.
+ */
+vi.unmock('@/tools/registry')
+
 describe('indexWorkflowSearchMatches', () => {
   it('finds plain text matches across nested subblock values', () => {
     const workflow = createSearchReplaceWorkflowFixture()
diff --git a/apps/sim/lib/workflows/search-replace/replacements.test.ts b/apps/sim/lib/workflows/search-replace/replacements.test.ts
index 354dff37f8c..340fa434350 100644
--- a/apps/sim/lib/workflows/search-replace/replacements.test.ts
+++ b/apps/sim/lib/workflows/search-replace/replacements.test.ts
@@ -10,6 +10,17 @@ import {
 } from '@/lib/workflows/search-replace/search-replace.fixtures'
 import { WORKFLOW_SEARCH_SUBFLOW_FIELD_IDS } from '@/lib/workflows/search-replace/subflow-fields'
 
+/**
+ * Uses the real tool registry. Nothing here imports it directly — the dependency
+ * is transitive: the search-replace planner resolves tool input params through
+ * real subblock configs, so the global `@/tools/registry` mock in
+ * vitest.setup.ts empties the data these assertions read.
+ *
+ * Not a no-op, despite the lack of a direct import. Dropping this opt-out fails
+ * 8 tests across this file and its sibling suite.
+ */
+vi.unmock('@/tools/registry')
+
 describe('buildWorkflowSearchReplacePlan', () => {
   it('replaces selected text ranges across blocks without touching unselected matches', () => {
     const workflow = createSearchReplaceWorkflowFixture()
diff --git a/apps/sim/tools/azure_devops/azure-devops.test.ts b/apps/sim/tools/azure_devops/azure-devops.test.ts
index 104232b18a5..520b143675e 100644
--- a/apps/sim/tools/azure_devops/azure-devops.test.ts
+++ b/apps/sim/tools/azure_devops/azure-devops.test.ts
@@ -45,6 +45,12 @@ const baseParams = {
   accessToken: 'pat-token',
 }
 
+/**
+ * Uses the real tool registry: these assertions are about tool registration and
+ * params, which the global `@/tools/registry` mock in vitest.setup.ts empties.
+ */
+vi.unmock('@/tools/registry')
+
 const authHeader = `Basic ${Buffer.from(':pat-token').toString('base64')}`
 
 const allTools = [
diff --git a/apps/sim/vitest.config.ts b/apps/sim/vitest.config.ts
index cd5eea87377..453c0009b74 100644
--- a/apps/sim/vitest.config.ts
+++ b/apps/sim/vitest.config.ts
@@ -25,13 +25,6 @@ export default defineConfig({
     fileParallelism: true,
     maxConcurrency: 10,
     testTimeout: 10000,
-    deps: {
-      optimizer: {
-        web: {
-          enabled: true,
-        },
-      },
-    },
   },
   resolve: {
     alias: [
diff --git a/apps/sim/vitest.setup.ts b/apps/sim/vitest.setup.ts
index 82760d33715..25c34639607 100644
--- a/apps/sim/vitest.setup.ts
+++ b/apps/sim/vitest.setup.ts
@@ -97,6 +97,20 @@ vi.mock('@/stores/execution/store', () => ({
   useLastRunEdges: vi.fn().mockReturnValue(new Map()),
 }))
 
+/**
+ * The tool registry is 4,351 entries pulling ~5,907 modules, and almost nothing
+ * under test needs the real thing — but every test file that transitively
+ * reaches it paid to import the whole graph. Measured on the full suite:
+ * import 1,347s -> 633s, transform 130s -> 53s.
+ *
+ * `@/blocks/registry` is mocked the same way directly below, for the same reason.
+ *
+ * Tests that genuinely assert registration or tool params opt out with
+ * `vi.unmock('@/tools/registry')` at the top of the file — see
+ * blocks/blocks/outlook.test.ts for the pattern.
+ */
+vi.mock('@/tools/registry', () => ({ tools: {} }))
+
 vi.mock('@/blocks/registry', () => ({
   getBlock: vi.fn(() => ({
     name: 'Mock Block',
@@ -107,6 +121,8 @@ vi.mock('@/blocks/registry', () => ({
   })),
   getAllBlocks: vi.fn(() => []),
   getLatestBlock: vi.fn(() => undefined),
+  /** Mirrors the real module's accessor; without it consumers get "not a function". */
+  getBlockRegistry: vi.fn(() => ({})),
   getBlockByToolName: vi.fn((toolName: string) =>
     toolName.startsWith('gmail_')
       ? {