diff --git a/.travis.yml b/.travis.yml
index 4c3b9ba1..4077ac49 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,6 +8,21 @@ cache:
 
 matrix:
   include:
+    - name: 'Lowest versions of the dependencies'
+      os: linux
+      node_js: "10"
+      env: JOB_PART=test
+      install:
+        - rm yarn.lock
+        - node ./scripts/force-lowest-dependencies
+        - yarn
+    - name: 'Highest versions of the dependencies'
+      os: linux
+      node_js: "10"
+      env: JOB_PART=test
+      install:
+        - rm yarn.lock
+        - yarn
     - os: linux
       node_js: "10"
       env: JOB_PART=travis:lint
diff --git a/scripts/force-lowest-dependencies.js b/scripts/force-lowest-dependencies.js
new file mode 100755
index 00000000..42883986
--- /dev/null
+++ b/scripts/force-lowest-dependencies.js
@@ -0,0 +1,128 @@
+/*
+ * This file is part of the Symfony Webpack Encore package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+'use strict';
+
+const fs = require('fs');
+const childProcess = require('child_process');
+
+function getLowestVersion(dependency, range) {
+    return new Promise((resolve, reject) => {
+        childProcess.exec(
+            `npm view "${dependency}@${range}" version`,
+            { encoding: 'utf-8' },
+            (error, stdout) => {
+                if (error) {
+                    reject(`Could not retrieve versions list for "${dependency}@${range}"`);
+                    return;
+                }
+
+                const versions = stdout
+                    .split('\n')
+                    .filter(line => line);
+
+                if (versions.length === 0) {
+                    reject(`Could not find a lowest version for "${dependency}@${range}"`);
+                    return;
+                }
+
+                const parts = versions[0].split(' ');
+
+                // If there is only one version available that version
+                // is directly printed as the output of npm view.
+                if (parts.length === 1) {
+                    resolve([dependency, parts[0]]);
+                    return;
+                }
+
+                // If multiple versions are available then it outputs
+                // multiple lines matching the following format:
+                // <package>@<version> '<version>'
+                if (parts.length === 2) {
+                    resolve([dependency, parts[1].replace(/'/g, '')]);
+                    return;
+                }
+
+                reject(`Unexpected response for "${dependency}@${range}": ${versions[0]}`);
+            }
+        );
+    });
+}
+
+fs.readFile('package.json', (error, data) => {
+    if (error) {
+        throw error;
+    }
+
+    const packageInfo = JSON.parse(data);
+
+    const dependencyPromises = [];
+    if (packageInfo.dependencies) {
+        for (const dependency in packageInfo.dependencies) {
+            dependencyPromises.push(getLowestVersion(
+                dependency,
+                packageInfo.dependencies[dependency]
+            ));
+        }
+    }
+
+    const devDependencyPromises = [];
+    if (packageInfo.devDependencies) {
+        for (const devDependency in packageInfo.devDependencies) {
+            devDependencyPromises.push(getLowestVersion(
+                devDependency,
+                packageInfo.devDependencies[devDependency]
+            ));
+        }
+    }
+
+    const dependenciesUpdate = Promise.all(dependencyPromises).then(versions => {
+        versions.forEach(version => {
+            packageInfo.dependencies[version[0]] = version[1];
+        });
+    });
+
+    const devDependenciesUpdate = Promise.all(devDependencyPromises).then(versions => {
+        versions.forEach(version => {
+            packageInfo.devDependencies[version[0]] = version[1];
+        });
+    });
+
+    // Once all the lowest versions have been resolved, update the
+    // package.json file accordingly.
+    Promise
+        .all([dependenciesUpdate, devDependenciesUpdate])
+        .then(() => new Promise((resolve, reject) => {
+            fs.writeFile('package.json', JSON.stringify(packageInfo, null, 2), (error) => {
+                if (error) {
+                    reject(error);
+                    return;
+                }
+
+                resolve();
+            });
+        }))
+        .then(() => {
+            console.log('Updated package.json file with lowest dependency versions: ');
+
+            console.log('Dependencies:');
+            for (const dependency in packageInfo.dependencies) {
+                console.log(`  - ${dependency}: ${packageInfo.dependencies[dependency]}`);
+            }
+
+            console.log('Dev dependencies:');
+            for (const dependency in packageInfo.devDependencies) {
+                console.log(`  - ${dependency}: ${packageInfo.devDependencies[dependency]}`);
+            }
+        })
+        .catch(error => {
+            console.error(error);
+            process.exit(1); // eslint-disable-line
+        });
+});
diff --git a/test/package-helper.js b/test/package-helper.js
index 23defca1..5daf63d9 100644
--- a/test/package-helper.js
+++ b/test/package-helper.js
@@ -13,6 +13,7 @@ const expect = require('chai').expect;
 const packageHelper = require('../lib/package-helper');
 const path = require('path');
 const process = require('process');
+const fs = require('fs');
 
 describe('package-helper', () => {
     const baseCwd = process.cwd();
@@ -135,14 +136,17 @@ describe('package-helper', () => {
 
     describe('addPackagesVersionConstraint', () => {
         it('Lookup a version constraint', () => {
-            // hardcoding sass-loader: test WILL break when this changes
-
             const inputPackages = [
                 { name: 'sass-loader', enforce_version: 7 },
                 { name: 'node-sass' }
             ];
+
+            const packageInfo = JSON.parse(
+                fs.readFileSync(path.join(__dirname, '../package.json'))
+            );
+
             const expectedPackages = [
-                { name: 'sass-loader', version: '^7.0.1' },
+                { name: 'sass-loader', version: packageInfo.devDependencies['sass-loader'] },
                 { name: 'node-sass' }
             ];