diff --git a/lib/portfinder.js b/lib/portfinder.js
index d68b4d9..e692947 100644
--- a/lib/portfinder.js
+++ b/lib/portfinder.js
@@ -124,11 +124,6 @@ exports.setBasePath = function (path) {
 };
 
 internals.getPort = function (options, callback) {
-  if (!callback) {
-    callback = options;
-    options = {};
-  }
-
   options.port   = Number(options.port) || Number(exports.basePort);
   options.host   = options.host    || null;
   options.stopPort = Number(options.stopPort) || Number(exports.highestPort);
@@ -139,7 +134,7 @@ internals.getPort = function (options, callback) {
       throw Error('Provided options.startPort(' + options.startPort + ') is less than 0, which are cannot be bound.');
     }
     if(options.stopPort < options.startPort) {
-      throw Error('Provided options.stopPort(' + options.stopPort + 'is less than options.startPort (' + options.startPort + ')');
+      throw Error('Provided options.stopPort(' + options.stopPort + ') is less than options.startPort (' + options.startPort + ')');
     }
   }
 
@@ -182,7 +177,7 @@ internals.getPort = function (options, callback) {
         } else {
           const idx = exports._defaultHosts.indexOf(currentHost);
           exports._defaultHosts.splice(idx, 1);
-          return exports.getPort(options, callback);
+          return internals.getPort(options, callback);
         }
       } else {
         // error is not accounted for, file ticket, handle special case
@@ -208,7 +203,7 @@ internals.getPort = function (options, callback) {
       }
     } else {
       // otherwise, try again, using sorted port, aka, highest open for >= 1 host
-      return exports.getPort({ port: openPorts.pop(), host: options.host, startPort: options.startPort, stopPort: options.stopPort }, callback);
+      return internals.getPort({ port: openPorts.pop(), host: options.host, startPort: options.startPort, stopPort: options.stopPort }, callback);
     }
 
   });
@@ -220,11 +215,13 @@ internals.getPort = function (options, callback) {
 // Responds with a unbound port on the current machine.
 //
 exports.getPort = function (options, callback) {
-  if (!callback) {
+  if (typeof options === 'function') {
     callback = options;
     options = {};
   }
 
+  options = options || {};
+
   if (!callback) {
     return new Promise(function (resolve, reject) {
       internals.getPort(options, function (err, port) {
@@ -247,18 +244,13 @@ exports.getPort = function (options, callback) {
 exports.getPortPromise = exports.getPort;
 
 internals.getPorts = function (count, options, callback) {
-  if (!callback) {
-    callback = options;
-    options = {};
-  }
-
   let lastPort = null;
   _async.timesSeries(count, function(index, asyncCallback) {
     if (lastPort) {
       options.port = exports.nextPort(lastPort);
     }
 
-    exports.getPort(options, function (err, port) {
+    internals.getPort(options, function (err, port) {
       if (err) {
         asyncCallback(err);
       } else {
@@ -277,11 +269,13 @@ internals.getPorts = function (count, options, callback) {
 // Responds with an array of unbound ports on the current machine.
 //
 exports.getPorts = function (count, options, callback) {
-  if (!callback) {
+  if (typeof options === 'function') {
     callback = options;
     options = {};
   }
 
+  options = options || {};
+
   if (!callback) {
     return new Promise(function(resolve, reject) {
       internals.getPorts(count, options, function(err, ports) {
diff --git a/test/port-finder-multiple.test.js b/test/port-finder-multiple.test.js
index 5ef97e0..dfe5ec4 100644
--- a/test/port-finder-multiple.test.js
+++ b/test/port-finder-multiple.test.js
@@ -22,35 +22,84 @@ describe('with 5 existing servers', function () {
     helper.stopServers(servers, done);
   });
 
-  test('the getPorts() method with an argument of 3 should respond with the first three available ports (32773, 32774, 32775)', function (done) {
-    portfinder.getPorts(3, function (err, ports) {
-      expect(err).toBeNull();
-      expect(ports).toEqual([32773, 32774, 32775]);
-      done();
+  describe.each([
+    ['getPorts()', false, portfinder.getPorts],
+    ['getPorts()', true, portfinder.getPorts],
+    ['getPortsPromise()', true, portfinder.getPortsPromise],
+  ])(`the %s method (promise: %p)`, function (name, isPromise, method) {
+    test('with an argument of 3 should respond with the first three available ports (32773, 32774, 32775)', function (done) {
+      if (isPromise) {
+        method(3)
+          .then(function (ports) {
+            expect(ports).toEqual([32773, 32774, 32775]);
+            done();
+          })
+          .catch(function (err) {
+            done(err);
+          });
+      } else {
+        method(3, function (err, ports) {
+          if (err) {
+            done(err);
+            return;
+          }
+          expect(err).toBeNull();
+          expect(ports).toEqual([32773, 32774, 32775]);
+          done();
+        });
+      }
+    });
+
+    test('with stopPort smaller than 3 available ports', function (done) {
+      if (isPromise) {
+        method(3, { stopPort: 32774 })
+          .then(function () {
+            done('Expected error to be thrown');
+          })
+          .catch(function (err) {
+            expect(err).not.toBeNull();
+            expect(err.message).toEqual('No open ports found in between 32768 and 32774');
+            done();
+          });
+      } else {
+        method(3, { stopPort: 32774 }, function (err, ports) {
+          expect(err).not.toBeNull();
+          expect(err.message).toEqual('No open ports found in between 32768 and 32774');
+          expect(ports).toEqual([32773, 32774, undefined]);
+          done();
+        });
+      }
     });
   });
 });
 
 describe('with no existing servers', function () {
-  test('the getPorts() method with an argument of 3 should respond with the first three available ports (32768, 32769, 32770)', function (done) {
-    portfinder.getPorts(3, function (err, ports) {
-      expect(err).toBeNull();
-      expect(ports).toEqual([32768, 32769, 32770]);
-      done();
+  describe.each([
+    ['getPorts()', false, portfinder.getPorts],
+    ['getPorts()', true, portfinder.getPorts],
+    ['getPortsPromise()', true, portfinder.getPortsPromise],
+  ])(`the %s method (promise: %p)`, function (name, isPromise, method) {
+    test('with an argument of 3 should respond with the first three available ports (32768, 32769, 32770)', function (done) {
+      if (isPromise) {
+        method(3)
+          .then(function (ports) {
+            expect(ports).toEqual([32768, 32769, 32770]);
+            done();
+          })
+          .catch(function (err) {
+            done(err);
+          });
+      } else {
+        method(3, function (err, ports) {
+          if (err) {
+            done(err);
+            return;
+          }
+          expect(err).toBeNull();
+          expect(ports).toEqual([32768, 32769, 32770]);
+          done();
+        });
+      }
     });
   });
-
-  test.each([
-    ['getPorts()', portfinder.getPorts],
-    ['getPortsPromise()', portfinder.getPortsPromise],
-  ])('the %s promise method with an argument of 3 should respond with the first three available ports (32768, 32769, 32770)', function (name, method, done) {
-    method(3)
-      .then(function (ports) {
-        expect(ports).toEqual([32768, 32769, 32770]);
-        done();
-      })
-      .catch(function (err) {
-        done(err);
-      });
-  });
 });
diff --git a/test/port-finder.test.js b/test/port-finder.test.js
index 6099ba8..b463780 100644
--- a/test/port-finder.test.js
+++ b/test/port-finder.test.js
@@ -22,94 +22,162 @@ describe('with 5 existing servers', function () {
     helper.stopServers(servers, done);
   });
 
-  test('should respond with the first free port (32773)', function (done) {
-    // closeServers(); // close all the servers first!
-    portfinder.getPort(function (err, port) {
-      expect(err).toBeNull();
-      expect(port).toEqual(32773);
-      done();
+  describe.each([
+    ['getPort()', false, portfinder.getPort],
+    ['getPort()', true, portfinder.getPort],
+    ['getPortPromise()', true, portfinder.getPortPromise],
+  ])(`the %s method (promise: %p)`, function (name, isPromise, method) {
+    test('should respond with the first free port (32773)', function (done) {
+      if (isPromise) {
+        method()
+          .then(function (port) {
+            expect(port).toEqual(32773);
+            done();
+          })
+          .catch(function (err) {
+            done(err);
+          });
+      } else {
+        method(function (err, port) {
+          if (err) {
+            done(err);
+            return;
+          }
+          expect(err).toBeNull();
+          expect(port).toEqual(32773);
+          done();
+        });
+      }
     });
-  });
 
-  test('the getPort() method with user passed duplicate host', function (done) {
-    portfinder.getPort({ host: 'localhost' }, function (err, port) {
-      expect(err).toBeNull();
-      expect(port).toEqual(32773);
-      done();
+    test('with user passed duplicate host', function (done) {
+      if (isPromise) {
+        method({ host: 'localhost' })
+          .then(function (port) {
+            expect(port).toEqual(32773);
+            done();
+          })
+          .catch(function (err) {
+            done(err);
+          });
+      } else {
+        method({ host: 'localhost' }, function (err, port) {
+          if (err) {
+            done(err);
+            return;
+          }
+          expect(err).toBeNull();
+          expect(port).toEqual(32773);
+          done();
+        });
+      }
     });
-  });
 
-  test('the getPort() method with stopPort smaller than available port', function (done) {
-    // stopPort: 32722 is smaller than available port 32773 (32768 + 5)
-    portfinder.getPort({ stopPort: 32772 }, function (err, port) {
-      expect(err).not.toBeNull();
-      expect(err.message).toEqual('No open ports found in between 32768 and 32772');
-      expect(port).toBeUndefined();
-      done();
+    test('with stopPort smaller than available port', function (done) {
+      // stopPort: 32772 is smaller than available port 32773 (32768 + 5)
+      if (isPromise) {
+        method({ stopPort: 32772 })
+          .then(function () {
+            done('Expected error to be thrown');
+          })
+          .catch(function (err) {
+            expect(err).not.toBeNull();
+            expect(err.message).toEqual('No open ports found in between 32768 and 32772');
+            done();
+          });
+      } else {
+        method({ stopPort: 32772 }, function (err, port) {
+          expect(err).not.toBeNull();
+          expect(err.message).toEqual('No open ports found in between 32768 and 32772');
+          expect(port).toBeUndefined();
+          done();
+        });
+      }
     });
-  });
 
-  test('should respond with the first free port (32773) less than provided stopPort', function (done) {
-    // stopPort: 32774 is greater than available port 32773 (32768 + 5)
-    portfinder.getPort({ stopPort: 32774 }, function (err, port) {
-      if (err) {
-        done(err);
-        return;
+    test('should respond with the first free port (32773) less than provided stopPort', function (done) {
+      // stopPort: 32774 is greater than available port 32773 (32768 + 5)
+      if (isPromise) {
+        method({ stopPort: 32774 })
+          .then(function (port) {
+            expect(port).toEqual(32773);
+            done();
+          })
+          .catch(function (err) {
+            done(err);
+          });
+      } else {
+        method({ stopPort: 32774 }, function (err, port) {
+          if (err) {
+            done(err);
+            return;
+          }
+          expect(err).toBeNull();
+          expect(port).toEqual(32773);
+          done();
+        });
       }
-      expect(err).toBeNull();
-      expect(port).toEqual(32773);
-      done();
     });
   });
-
-  test.each([
-    ['getPort()', portfinder.getPort],
-    ['getPortPromise()', portfinder.getPortPromise],
-  ])('the %s promise method should respond with the first free port (32773)', function (name, method, done) {
-    method()
-      .then(function (port) {
-        expect(port).toEqual(32773);
-        done();
-      })
-      .catch(function (err) {
-        done(err);
-      });
-  });
 });
 
 describe('with no existing servers', function () {
-  test('should respond with the first free port (32768)', function (done) {
-    portfinder.getPort(function (err, port) {
-      if (err) {
-        done(err);
-        return;
+  describe.each([
+    ['getPort()', false, portfinder.getPort],
+    ['getPort()', true, portfinder.getPort],
+    ['getPortPromise()', true, portfinder.getPortPromise],
+  ])(`the %s method (promise: %p)`, function (name, isPromise, method) {
+    test('should respond with the first free port (32768)', function (done) {
+      if (isPromise) {
+        method()
+          .then(function (port) {
+            expect(port).toEqual(32768);
+            done();
+          })
+          .catch(function (err) {
+            done(err);
+          });
+      } else {
+        method(function (err, port) {
+          if (err) {
+            done(err);
+            return;
+          }
+          expect(err).toBeNull();
+          expect(port).toEqual(32768);
+          done();
+        });
       }
-      expect(err).toBeNull();
-      expect(port).toEqual(32768);
-      done();
     });
   });
+});
 
-  test.each([
-    ['getPort()', portfinder.getPort],
-    ['getPortPromise()', portfinder.getPortPromise],
-  ])('the %s promise method should respond with a promise of first free port (32768)', function (name, method, done) {
-    method()
-      .then(function (port) {
-        expect(port).toEqual(32768);
+describe.each([
+  ['getPort()', false, portfinder.getPort],
+  ['getPort()', true, portfinder.getPort],
+  ['getPortPromise()', true, portfinder.getPortPromise],
+])(`the %s method (promise: %p)`, function (name, isPromise, method) {
+  test('with startPort less than or equal to 80', function (done) {
+    if (isPromise) {
+      method({ startPort: 80 })
+        .then(function (port) {
+          expect(port).toBeGreaterThanOrEqual(80);
+          done();
+        })
+        .catch(function (err) {
+          done(err);
+        });
+    } else {
+      method({ startPort: 80 }, function (err, port) {
+        if (err) {
+          done(err);
+          return;
+        }
+        expect(err).toBeNull();
+        expect(port).toBeGreaterThanOrEqual(80);
         done();
-      })
-      .catch(function (err) {
-        done(err);
       });
-  });
-});
-
-test('the getPort() method with startPort less than or equal to 80', function (done) {
-  portfinder.getPort({ startPort: 80 }, function (err, port) {
-    expect(err).toBeNull();
-    expect(port).toBeGreaterThanOrEqual(80);
-    done();
+    }
   });
 });
 
@@ -122,12 +190,30 @@ describe('with no available ports above the start port', function () {
     helper.stopServers(servers, done);
   });
 
-  test('the getPort() method requesting an unavailable port', function (done) {
-    portfinder.getPort({ port: 65530 }, function (err, port) {
-      expect(err).not.toBeNull();
-      expect(err.message).toEqual('No open ports available');
-      expect(port).toBeUndefined();
-      done();
+  describe.each([
+    ['getPort()', false, portfinder.getPort],
+    ['getPort()', true, portfinder.getPort],
+    ['getPortPromise()', true, portfinder.getPortPromise],
+  ])(`the %s method (promise: %p)`, function (name, isPromise, method) {
+    test('the getPort() method requesting an unavailable port', function (done) {
+      if (isPromise) {
+        method({ port: 65530 })
+          .then(function () {
+            done('Expected error to be thrown');
+          })
+          .catch(function (err) {
+            expect(err).not.toBeNull();
+            expect(err.message).toEqual('No open ports available');
+            done();
+          });
+      } else {
+        method({ port: 65530 }, function (err, port) {
+          expect(err).not.toBeNull();
+          expect(err.message).toEqual('No open ports available');
+          expect(port).toBeUndefined();
+          done();
+        });
+      }
     });
   });
 });