diff --git a/packages/@aws-cdk/aws-apigateway/lib/authorizers/lambda.ts b/packages/@aws-cdk/aws-apigateway/lib/authorizers/lambda.ts
index a354c8a4b3196..f7be4f954d7e8 100644
--- a/packages/@aws-cdk/aws-apigateway/lib/authorizers/lambda.ts
+++ b/packages/@aws-cdk/aws-apigateway/lib/authorizers/lambda.ts
@@ -1,6 +1,6 @@
 import * as iam from '@aws-cdk/aws-iam';
 import * as lambda from '@aws-cdk/aws-lambda';
-import { Duration, Lazy, Names, Stack } from '@aws-cdk/core';
+import { Arn, ArnFormat, Duration, Lazy, Names, Stack } from '@aws-cdk/core';
 import { Construct } from 'constructs';
 import { CfnAuthorizer } from '../apigateway.generated';
 import { Authorizer, IAuthorizer } from '../authorizer';
@@ -254,5 +254,6 @@ export class RequestAuthorizer extends LambdaAuthorizer {
  * constructs the authorizerURIArn.
  */
 function lambdaAuthorizerArn(handler: lambda.IFunction) {
-  return `arn:${Stack.of(handler).partition}:apigateway:${Stack.of(handler).region}:lambda:path/2015-03-31/functions/${handler.functionArn}/invocations`;
+  const { region, partition } = Arn.split( handler.functionArn, ArnFormat.COLON_RESOURCE_NAME);
+  return `arn:${partition}:apigateway:${region}:lambda:path/2015-03-31/functions/${handler.functionArn}/invocations`;
 }
diff --git a/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.request-authorizer.lit.expected.json b/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.request-authorizer.lit.expected.json
index 9768e9692a548..981f02ebed888 100644
--- a/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.request-authorizer.lit.expected.json
+++ b/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.request-authorizer.lit.expected.json
@@ -253,11 +253,37 @@
             [
               "arn:",
               {
-                "Ref": "AWS::Partition"
+                "Fn::Select": [
+                  1,
+                  {
+                    "Fn::Split": [
+                      ":",
+                      {
+                        "Fn::GetAtt": [
+                          "MyAuthorizerFunction70F1223E",
+                          "Arn"
+                        ]
+                      }
+                    ]
+                  }
+                ]
               },
               ":apigateway:",
               {
-                "Ref": "AWS::Region"
+                "Fn::Select": [
+                  3,
+                  {
+                    "Fn::Split": [
+                      ":",
+                      {
+                        "Fn::GetAtt": [
+                          "MyAuthorizerFunction70F1223E",
+                          "Arn"
+                        ]
+                      }
+                    ]
+                  }
+                ]
               },
               ":lambda:path/2015-03-31/functions/",
               {
diff --git a/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer-iam-role.expected.json b/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer-iam-role.expected.json
index b3d35baa2e42c..eda922f948d66 100644
--- a/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer-iam-role.expected.json
+++ b/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer-iam-role.expected.json
@@ -122,11 +122,37 @@
             [
               "arn:",
               {
-                "Ref": "AWS::Partition"
+                "Fn::Select": [
+                  1,
+                  {
+                    "Fn::Split": [
+                      ":",
+                      {
+                        "Fn::GetAtt": [
+                          "MyAuthorizerFunction70F1223E",
+                          "Arn"
+                        ]
+                      }
+                    ]
+                  }
+                ]
               },
               ":apigateway:",
               {
-                "Ref": "AWS::Region"
+                "Fn::Select": [
+                  3,
+                  {
+                    "Fn::Split": [
+                      ":",
+                      {
+                        "Fn::GetAtt": [
+                          "MyAuthorizerFunction70F1223E",
+                          "Arn"
+                        ]
+                      }
+                    ]
+                  }
+                ]
               },
               ":lambda:path/2015-03-31/functions/",
               {
diff --git a/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer.lit.expected.json b/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer.lit.expected.json
index f36705d28f193..237a238eefcaa 100644
--- a/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer.lit.expected.json
+++ b/packages/@aws-cdk/aws-apigateway/test/authorizers/integ.token-authorizer.lit.expected.json
@@ -253,11 +253,37 @@
             [
               "arn:",
               {
-                "Ref": "AWS::Partition"
+                "Fn::Select": [
+                  1,
+                  {
+                    "Fn::Split": [
+                      ":",
+                      {
+                        "Fn::GetAtt": [
+                          "MyAuthorizerFunction70F1223E",
+                          "Arn"
+                        ]
+                      }
+                    ]
+                  }
+                ]
               },
               ":apigateway:",
               {
-                "Ref": "AWS::Region"
+                "Fn::Select": [
+                  3,
+                  {
+                    "Fn::Split": [
+                      ":",
+                      {
+                        "Fn::GetAtt": [
+                          "MyAuthorizerFunction70F1223E",
+                          "Arn"
+                        ]
+                      }
+                    ]
+                  }
+                ]
               },
               ":lambda:path/2015-03-31/functions/",
               {
diff --git a/packages/@aws-cdk/aws-apigateway/test/authorizers/lambda.test.ts b/packages/@aws-cdk/aws-apigateway/test/authorizers/lambda.test.ts
index fdaa20af10cd3..6728e0204ed37 100644
--- a/packages/@aws-cdk/aws-apigateway/test/authorizers/lambda.test.ts
+++ b/packages/@aws-cdk/aws-apigateway/test/authorizers/lambda.test.ts
@@ -35,11 +35,31 @@ describe('lambda authorizer', () => {
           [
             'arn:',
             {
-              Ref: 'AWS::Partition',
+              'Fn::Select': [
+                1,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':apigateway:',
             {
-              Ref: 'AWS::Region',
+              'Fn::Select': [
+                3,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':lambda:path/2015-03-31/functions/',
             {
@@ -89,11 +109,31 @@ describe('lambda authorizer', () => {
           [
             'arn:',
             {
-              Ref: 'AWS::Partition',
+              'Fn::Select': [
+                1,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':apigateway:',
             {
-              Ref: 'AWS::Region',
+              'Fn::Select': [
+                3,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':lambda:path/2015-03-31/functions/',
             {
@@ -167,11 +207,31 @@ describe('lambda authorizer', () => {
           [
             'arn:',
             {
-              Ref: 'AWS::Partition',
+              'Fn::Select': [
+                1,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':apigateway:',
             {
-              Ref: 'AWS::Region',
+              'Fn::Select': [
+                3,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':lambda:path/2015-03-31/functions/',
             {
@@ -218,11 +278,31 @@ describe('lambda authorizer', () => {
           [
             'arn:',
             {
-              Ref: 'AWS::Partition',
+              'Fn::Select': [
+                1,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':apigateway:',
             {
-              Ref: 'AWS::Region',
+              'Fn::Select': [
+                3,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':lambda:path/2015-03-31/functions/',
             {
@@ -269,11 +349,31 @@ describe('lambda authorizer', () => {
           [
             'arn:',
             {
-              Ref: 'AWS::Partition',
+              'Fn::Select': [
+                1,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':apigateway:',
             {
-              Ref: 'AWS::Region',
+              'Fn::Select': [
+                3,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':lambda:path/2015-03-31/functions/',
             {
@@ -341,11 +441,31 @@ describe('lambda authorizer', () => {
           [
             'arn:',
             {
-              Ref: 'AWS::Partition',
+              'Fn::Select': [
+                1,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':apigateway:',
             {
-              Ref: 'AWS::Region',
+              'Fn::Select': [
+                3,
+                {
+                  'Fn::Split': [
+                    ':',
+                    {
+                      'Fn::GetAtt': ['myfunction9B95E948', 'Arn'],
+                    },
+                  ],
+                },
+              ],
             },
             ':lambda:path/2015-03-31/functions/',
             {