diff --git a/lib/config.js b/lib/config.js
index 124cb41..d1dd1a2 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -14,6 +14,7 @@ function defaults() {
   CONFIG.ACTION_DELETE_OBJECT = false;
   CONFIG.MAX_ATTEMPTS = 10;
   CONFIG.MAX_ATTEMPT_DELAY_MSEC = 30_000;
+  CONFIG.SIGNED_URL_DURATION = 3600
 
 // extracting config overwrites from the environment:
   if (process.env.API_KEY) {
@@ -47,6 +48,10 @@ function defaults() {
     CONFIG.MAX_ATTEMPT_DELAY_MSEC = process.env.MAX_ATTEMPT_DELAY_MSEC;
   }
 
+  if (process.env.SIGNED_URL_DURATION) {
+    CONFIG.SIGNED_URL_DURATION = process.env.SIGNED_URL_DURATION;
+  }
+
 }
 
 defaults();
diff --git a/lib/s3-handler.js b/lib/s3-handler.js
index 05b97de..2110984 100644
--- a/lib/s3-handler.js
+++ b/lib/s3-handler.js
@@ -42,11 +42,10 @@ exports.handler = async (event, context, callback) => {
     console.log('processing ' + utils.internalId(bucket, key));
 
     // creating signed url for processing - permissions are only checked at execution time
-    // https://forums.aws.amazon.com/thread.jspa?threadID=252897
     const url = S3.getSignedUrl('getObject', {
       Bucket: bucket,
       Key: key,
-      Expires: 3600 // 1 hour in seconds
+      Expires: CONFIG.SIGNED_URL_DURATION
     });
     console.log('created signed url', url);
 
diff --git a/tests/s3-handler.js b/tests/s3-handler.js
index 30a58be..65389e8 100644
--- a/tests/s3-handler.js
+++ b/tests/s3-handler.js
@@ -5,7 +5,7 @@ const it = require("mocha/lib/mocha.js").it;
 const describe = require("mocha/lib/mocha.js").describe;
 const beforeEach = require("mocha/lib/mocha.js").beforeEach;
 const afterEach = require("mocha/lib/mocha.js").afterEach;
-const AWS = require('aws-sdk');
+const AWS = require('aws-sdk-mock');
 const nock = require('nock');
 const CONFIG = require('../lib/config').CONFIG;
 const sinon = require('sinon');
@@ -19,13 +19,12 @@ describe('S3 handler tests', () => {
   beforeEach(() => {
     sandbox.spy(scanii.ScaniiClient);
 
-    // wrapping some fakes around the AWS sdk:
-    AWS.S3.prototype.getSignedUrl = () => 'https://example.com/1234?q=124';
     CONFIG.CALLBACK_URL = "https://example.com/callback/";
     CONFIG.KEY = "k";
     CONFIG.SECRET = "s";
     CONFIG.MAX_ATTEMPTS = 1;
     CONFIG.MAX_ATTEMPT_DELAY_MSEC = 1_000;
+    CONFIG.SIGNED_URL_DURATION = 10;
   });
 
   afterEach(() => {
@@ -228,5 +227,60 @@ describe('S3 handler tests', () => {
       assert(result.body.includes("cannot process directory"));
     });
   });
-});
+  it('should honor configurable signed url timeout', async () => {
+
+    nock('https://api-us1.scanii.com')
+      .post('/v2.2/files/fetch')
+      .reply(202, Buffer.from("{\"id\":\"12356789\"}"), {"Location": "https://api-us1.scanii.com/v2.2/files/1234"});
+
+    AWS.mock('S3', 'getSignedUrl',  (operator,params) => {
+      assert.ok(params.Expires === CONFIG.SIGNED_URL_DURATION);
+      return true;
+    })
+
+    return await handler({
+      "Records": [
+        {
+          "eventVersion": "2.0",
+          "eventSource": "aws:s3",
+          "awsRegion": "us-west-2",
+          "eventTime": "2015-10-01T23:28:54.280Z",
+          "eventName": "ObjectCreated:Put",
+          "userIdentity": {
+            "principalId": "AWS:principal"
+          },
+          "requestParameters": {
+            "sourceIPAddress": "98.167.155.191"
+          },
+          "responseElements": {
+            "x-amz-request-id": "EEC943B096DE3DF9",
+            "x-amz-id-2": "W/myEjyXFBsOA6N0byxW0tOxMA4m1fmv9KAVcovvG0nD9W1s5aX5+Wx61tlCop8LbZAw1Nz0mnc="
+          },
+          "s3": {
+            "s3SchemaVersion": "1.0",
+            "configurationId": "948c2c1a-a028-4564-93fc-76cea7622633",
+            "bucket": {
+              "name": "scanii-mu",
+              "ownerIdentity": {
+                "principalId": "principal"
+              },
+              "arn": "arn:aws:s3:::scanii-mu"
+            },
+            "object": {
+              "key": "Screen+Shot+2016-01-19+at+7.24.37+PM.png",
+              "size": 519,
+              "eTag": "aa1e5c8a6a07217c25f55aa8e96ea37a",
+              "sequencer": "00560DC1B62F962FCD"
+            }
+          }
+        }
+      ]
+
+    }, {}, (error, result) => {
+      assert.ok(error === null, "there should be no errors");
+      assert.ok(result.statusCode === 200, "signed url timeout not configurable");
+
+    });
+  });
+})