diff --git a/.projenrc.ts b/.projenrc.ts
index 45e1ee1fa..af457fc96 100644
--- a/.projenrc.ts
+++ b/.projenrc.ts
@@ -108,7 +108,7 @@ function sharedJestConfig(): pj.javascript.JestConfigOptions {
       'ts',
       'js',
     ],
-    maxWorkers: '80%',
+    maxWorkers: 1,
     testEnvironment: 'node',
     coverageThreshold: {
       statements: 80,
diff --git a/packages/@aws-cdk/cdk-cli-wrapper/jest.config.json b/packages/@aws-cdk/cdk-cli-wrapper/jest.config.json
index 5d8df7835..ec82d8c30 100644
--- a/packages/@aws-cdk/cdk-cli-wrapper/jest.config.json
+++ b/packages/@aws-cdk/cdk-cli-wrapper/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/cli-lib-alpha/jest.config.json b/packages/@aws-cdk/cli-lib-alpha/jest.config.json
index a95302a29..17903c223 100644
--- a/packages/@aws-cdk/cli-lib-alpha/jest.config.json
+++ b/packages/@aws-cdk/cli-lib-alpha/jest.config.json
@@ -1,6 +1,6 @@
 {
   "coverageProvider": "v8",
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/cli-plugin-contract/jest.config.json b/packages/@aws-cdk/cli-plugin-contract/jest.config.json
index 0304b3297..679238407 100644
--- a/packages/@aws-cdk/cli-plugin-contract/jest.config.json
+++ b/packages/@aws-cdk/cli-plugin-contract/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/cloud-assembly-schema/jest.config.json b/packages/@aws-cdk/cloud-assembly-schema/jest.config.json
index 6b3862481..304ca576a 100644
--- a/packages/@aws-cdk/cloud-assembly-schema/jest.config.json
+++ b/packages/@aws-cdk/cloud-assembly-schema/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/cloudformation-diff/jest.config.json b/packages/@aws-cdk/cloudformation-diff/jest.config.json
index 6b3862481..304ca576a 100644
--- a/packages/@aws-cdk/cloudformation-diff/jest.config.json
+++ b/packages/@aws-cdk/cloudformation-diff/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/integ-runner/jest.config.json b/packages/@aws-cdk/integ-runner/jest.config.json
index cb081731d..eea75522d 100644
--- a/packages/@aws-cdk/integ-runner/jest.config.json
+++ b/packages/@aws-cdk/integ-runner/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/node-bundle/jest.config.json b/packages/@aws-cdk/node-bundle/jest.config.json
index 16d45feb1..35af6c6f0 100644
--- a/packages/@aws-cdk/node-bundle/jest.config.json
+++ b/packages/@aws-cdk/node-bundle/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/tmp-toolkit-helpers/jest.config.json b/packages/@aws-cdk/tmp-toolkit-helpers/jest.config.json
index bffb87ec4..e04223adb 100644
--- a/packages/@aws-cdk/tmp-toolkit-helpers/jest.config.json
+++ b/packages/@aws-cdk/tmp-toolkit-helpers/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/toolkit-lib/jest.config.json b/packages/@aws-cdk/toolkit-lib/jest.config.json
index 89a9c20fc..bbf1488ca 100644
--- a/packages/@aws-cdk/toolkit-lib/jest.config.json
+++ b/packages/@aws-cdk/toolkit-lib/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "./test/_helpers/jest-bufferedconsole.ts",
   "coverageThreshold": {
     "global": {
diff --git a/packages/@aws-cdk/user-input-gen/jest.config.json b/packages/@aws-cdk/user-input-gen/jest.config.json
index 0304b3297..679238407 100644
--- a/packages/@aws-cdk/user-input-gen/jest.config.json
+++ b/packages/@aws-cdk/user-input-gen/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/aws-cdk/jest.config.json b/packages/aws-cdk/jest.config.json
index be8b208ed..2e8a0df51 100644
--- a/packages/aws-cdk/jest.config.json
+++ b/packages/aws-cdk/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "./test/_helpers/jest-bufferedconsole.ts",
   "coverageThreshold": {
     "global": {
diff --git a/packages/cdk-assets/jest.config.json b/packages/cdk-assets/jest.config.json
index 6cceb79df..bc31e08d9 100644
--- a/packages/cdk-assets/jest.config.json
+++ b/packages/cdk-assets/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {
diff --git a/packages/cdk/jest.config.json b/packages/cdk/jest.config.json
index 0304b3297..679238407 100644
--- a/packages/cdk/jest.config.json
+++ b/packages/cdk/jest.config.json
@@ -4,7 +4,7 @@
     "ts",
     "js"
   ],
-  "maxWorkers": "80%",
+  "maxWorkers": 14,
   "testEnvironment": "node",
   "coverageThreshold": {
     "global": {