diff --git a/osx/macosx-builder.py b/osx/macosx-builder.py
index 92a9916..652baaf 100644
--- a/osx/macosx-builder.py
+++ b/osx/macosx-builder.py
@@ -322,20 +322,25 @@ class MacosxBuilder(object):
         """
         self._print('Running PyInstaller...')
         os.chdir(self.work_path)
-        pyinstaller = Popen((self.python,
-                             self.pyinstaller,
-                             '--noconfirm',
-                             '--windowed',
-                             '--noupx',
-                             '--additional-hooks-dir', self.hooks_path,
-                             '--runtime-hook', os.path.join(self.hooks_path, 'rthook_openlp_pyqt4.py'),
-                             '--log-level=ERROR',
-                             # '--distpath', self.branch_path,
-                             # '-i', self.mac_icon,
-                             '-p', self.work_path,
-                             '-n', 'OpenLP',
-                             self.openlp_script),
-                            stdout=PIPE)
+        cmd = [self.python,
+               self.pyinstaller,
+               '--clean',
+               '--noconfirm',
+               '--windowed',
+               '--noupx',
+               '--additional-hooks-dir', self.hooks_path,
+               '--runtime-hook', os.path.join(self.hooks_path, 'rthook_openlp_pyqt4.py'),
+               '-i', self.mac_icon,
+               '-p', self.work_path,
+               '-n', 'OpenLP',
+               self.openlp_script]
+        if not self.args.verbose:
+            cmd.append('--log-level=ERROR')
+        else:
+            cmd.append('--log-level=DEBUG')
+        if self.args.devel:
+            cmd.append('-d')
+        pyinstaller = Popen(cmd, stdout=PIPE)
         output = pyinstaller.communicate()[0]
         code = pyinstaller.wait()
         if code != 0:
@@ -433,7 +438,10 @@ class MacosxBuilder(object):
         fr = open(self.bundle_info, 'r')
         fw = open(os.path.join(self.dist_app_path, 'Contents', os.path.basename(self.bundle_info)), 'w')
         text = fr.read()
-        text = text % {'openlp_version': self.version_string}
+        if self.args.devel:
+            text = text % {'openlp_version': self.version_string}
+        else:
+            text = text % {'openlp_version': self.version_tag}
         fw.write(text)
         fr.close()
         fw.close()
@@ -584,7 +592,7 @@ class MacosxBuilder(object):
             os.remove(dmg_file)
         # Create empty dmg file.
         size = self._get_directory_size(self.dist_app_path)  # in bytes.
-        size = size / (1024 * 1024)  # Convert to megabytes.
+        size = size / (1000 * 1000)  # Convert to megabytes.
         size += 10  # Additional space in .dmg for other files.
         self._print('... dmg disk size: %s' % size)
         self._run_command([self.hdiutil, 'create', dmg_file, '-ov', '-megabytes', str(size), '-fs', 'HFS+', '-volname',
@@ -602,7 +610,7 @@ class MacosxBuilder(object):
         # Copy OpenLP.app and other files to .dmg
         # TODO more reliable way to determine dmg_volume_path
         self._print('... Copying the app to the dmg: ' + dmg_volume_path)
-        self._run_command(['cp', '-r', self.dist_app_path, dmg_volume_path],
+        self._run_command(['cp', '-R', self.dist_app_path, dmg_volume_path],
                           'Could not copy app bundle, dmg creation failed.')
 
         # Set icon for dmg file.
diff --git a/pyinstaller-hooks/hook-ssl.py b/pyinstaller-hooks/hook-ssl.py
new file mode 100644
index 0000000..29aa55e
--- /dev/null
+++ b/pyinstaller-hooks/hook-ssl.py
@@ -0,0 +1,10 @@
+from PyInstaller.compat import is_darwin
+from PyInstaller.utils.hooks.hookutils import exec_statement
+
+if is_darwin:  # TODO check if this is needed on linux
+    datas = []
+    files = exec_statement("""
+import ssl
+print(ssl.get_default_verify_paths().cafile)""").strip().split()
+    for file in files:
+        datas.append((file, 'lib'))  # TODO find a way to make sure the bundled cafile is always named 'cert.pem'
diff --git a/pyinstaller-hooks/rthook_ssl.py b/pyinstaller-hooks/rthook_ssl.py
new file mode 100644
index 0000000..db0e3e5
--- /dev/null
+++ b/pyinstaller-hooks/rthook_ssl.py
@@ -0,0 +1,5 @@
+import os
+import sys
+
+if sys.platform == 'darwin':  # TODO check if this is needed on linux
+    os.environ['SSL_CERT_FILE'] = os.path.join(sys._MEIPASS, 'lib', 'cert.pem')
diff --git a/windows/windows-builder.py b/windows/windows-builder.py
index b16809b..6f8ef75 100644
--- a/windows/windows-builder.py
+++ b/windows/windows-builder.py
@@ -289,19 +289,26 @@ class WindowsBuilder(object):
         """
         self._print('Running PyInstaller...')
         os.chdir(self.branch_path)
-        pyinstaller = Popen((self.python, self.pyinstaller,
-                             '--noconfirm',
-                             '--windowed',
-                             '--noupx',
-                             '--additional-hooks-dir', self.hooks_path,
-                             '--runtime-hook', os.path.join(self.hooks_path, 'rthook_openlp_pyqt4.py'),
-                             '--log-level=DEBUG',
-                             '--distpath', self.dist_path_pyinst_arg,
-                             '-i', self.win32_icon,
-                             '-p', self.branch_path,
-                             '-n', 'OpenLP',
-                             self.openlp_script),
-                            stdout=PIPE)
+        cmd = [self.python,
+               self.pyinstaller,
+               '--clean',
+               '--noconfirm',
+               '--windowed',
+               '--noupx',
+               '--additional-hooks-dir', self.hooks_path,
+               '--runtime-hook', os.path.join(self.hooks_path, 'rthook_openlp_pyqt4.py'),
+               '--distpath', self.dist_path_pyinst_arg,
+               '-i', self.win32_icon,
+               '-p', self.branch_path,
+               '-n', 'OpenLP',
+               self.openlp_script]
+        if not self.args.verbose:
+            cmd.append('--log-level=ERROR')
+        else:
+            cmd.append('--log-level=DEBUG')
+        if self.args.devel:
+            cmd.append('-d')
+        pyinstaller = Popen(cmd, stdout=PIPE)
         output = pyinstaller.communicate()[0]
         code = pyinstaller.wait()
         if code != 0: