diff --git a/packages/aws-cdk-lib/region-info/build-tools/fact-tables.ts b/packages/aws-cdk-lib/region-info/build-tools/fact-tables.ts
index d6f47431d11f4..b545ef311f92c 100644
--- a/packages/aws-cdk-lib/region-info/build-tools/fact-tables.ts
+++ b/packages/aws-cdk-lib/region-info/build-tools/fact-tables.ts
@@ -227,7 +227,7 @@ export const CLOUDWATCH_LAMBDA_INSIGHTS_ARNS: { [key: string]: any } = {
       // US East (Ohio)
       'us-east-2': 'arn:aws:lambda:us-east-2:580247275435:layer:LambdaInsightsExtension-Arm64:7',
       // US West (N. California)
-      'us-west-1': 'arn:aws:lambda:us-west-1:580247275435:layer:LambdaInsightsExtension-Arm64:5',
+      'us-west-1': 'arn:aws:lambda:us-west-1:580247275435:layer:LambdaInsightsExtension-Arm64:3',
       // US West (Oregon)
       'us-west-2': 'arn:aws:lambda:us-west-2:580247275435:layer:LambdaInsightsExtension-Arm64:5',
       // Africa (Cape Town)
diff --git a/packages/aws-cdk-lib/region-info/test/__snapshots__/region-info.test.js.snap b/packages/aws-cdk-lib/region-info/test/__snapshots__/region-info.test.js.snap
index 8c0b8deb5b156..dff3496357fad 100644
--- a/packages/aws-cdk-lib/region-info/test/__snapshots__/region-info.test.js.snap
+++ b/packages/aws-cdk-lib/region-info/test/__snapshots__/region-info.test.js.snap
@@ -1155,7 +1155,7 @@ exports[`built-in data is correct 1`] = `
     "lambdaInsightsArmVersions": {
       "1.0.119.0": undefined,
       "1.0.135.0": undefined,
-      "1.0.229.0": "arn:aws:lambda:us-west-1:580247275435:layer:LambdaInsightsExtension-Arm64:5",
+      "1.0.229.0": "arn:aws:lambda:us-west-1:580247275435:layer:LambdaInsightsExtension-Arm64:3",
     },
     "lambdaInsightsVersions": {
       "1.0.119.0": "arn:aws:lambda:us-west-1:580247275435:layer:LambdaInsightsExtension:16",