diff --git a/src/libcalamares/PythonHelper.cpp b/src/libcalamares/PythonHelper.cpp
index 4dee34d35..a4bccf18a 100644
--- a/src/libcalamares/PythonHelper.cpp
+++ b/src/libcalamares/PythonHelper.cpp
@@ -53,6 +53,9 @@ variantToPyObject( const QVariant& variant )
     case QVariant::String:
         return bp::object( variant.toString().toStdString() );
 
+    case QVariant::Bool:
+        return bp::object( variant.toBool() );
+
     default:
         return bp::object();
     }
@@ -78,6 +81,9 @@ variantFromPyObject( const boost::python::object& pyObject )
     else if ( pyType == "str" )
         return QVariant( QString::fromStdString( bp::extract< std::string >( pyObject ) ) );
 
+    else if ( pyType == "bool" )
+        return QVariant( bp::extract< bool >( pyObject ) );
+
     else
         return QVariant();
 }
diff --git a/src/modules/grubcfg/grubcfg.conf b/src/modules/grubcfg/grubcfg.conf
new file mode 100644
index 000000000..608c9b2b4
--- /dev/null
+++ b/src/modules/grubcfg/grubcfg.conf
@@ -0,0 +1,13 @@
+---
+# If set to true, always creates /etc/default/grub from scratch even if the file
+# already existed. If set to false, edits the existing file instead.
+overwrite: false
+# Default entries to write to /etc/default/grub if it does not exist yet or if
+# we are overwriting it. Note that in addition, GRUB_CMDLINE_LINUX_DEFAULT and
+# GRUB_DISTRIBUTOR will always be written, with automatically detected values.
+defaults:
+    GRUB_TIMEOUT: 5
+    GRUB_DEFAULT: "saved"
+    GRUB_DISABLE_SUBMENU: true
+    GRUB_TERMINAL_OUTPUT: "console"
+    GRUB_DISABLE_RECOVERY: true
diff --git a/src/modules/grubcfg/main.py b/src/modules/grubcfg/main.py
index ffa165d5a..ecec4531a 100644
--- a/src/modules/grubcfg/main.py
+++ b/src/modules/grubcfg/main.py
@@ -29,9 +29,6 @@ def modify_grub_default(partitions, root_mount_point, distributor):
     use_splash = ""
     swap_uuid = ""
 
-    if not os.path.exists(default_dir):
-        return ("Directory does not exist", "The directory {} does not exist on "
-        "the target".format(default_dir))
     if os.path.exists(plymouth_bin):
         use_splash = "splash"
 
@@ -44,19 +41,51 @@ def modify_grub_default(partitions, root_mount_point, distributor):
     else:
         kernel_cmd = 'GRUB_CMDLINE_LINUX_DEFAULT="quiet %s"' % use_splash
 
+    distributor_line = "GRUB_DISTRIBUTOR='%s'" % distributor.replace("'", "'\\''")
+
     if not os.path.exists(default_dir):
         os.mkdir(default_dir)
 
-    with open(default_grub, 'r') as grub_file:
-        lines = [x.strip() for x in grub_file.readlines()]
+    have_kernel_cmd = False
+    have_distributor_line = False
 
-    for i in range(len(lines)):
-        if lines[i].startswith("#GRUB_CMDLINE_LINUX_DEFAULT"):
-            lines[i] = kernel_cmd
-        elif lines[i].startswith("GRUB_CMDLINE_LINUX_DEFAULT"):
-            lines[i] = kernel_cmd
-        elif lines[i].startswith("#GRUB_DISTRIBUTOR") or lines[i].startswith("GRUB_DISTRIBUTOR"):
-            lines[i] = "GRUB_DISTRIBUTOR='%s'" % distributor.replace("'", "'\\''")
+    if "overwrite" in libcalamares.job.configuration:
+        overwrite = libcalamares.job.configuration["overwrite"]
+    else:
+        overwrite = False
+
+    if os.path.exists(default_grub) and not overwrite:
+        with open(default_grub, 'r') as grub_file:
+            lines = [x.strip() for x in grub_file.readlines()]
+
+        for i in range(len(lines)):
+            if lines[i].startswith("#GRUB_CMDLINE_LINUX_DEFAULT"):
+                lines[i] = kernel_cmd
+                have_kernel_cmd = True
+            elif lines[i].startswith("GRUB_CMDLINE_LINUX_DEFAULT"):
+                lines[i] = kernel_cmd
+                have_kernel_cmd = True
+            elif lines[i].startswith("#GRUB_DISTRIBUTOR") or lines[i].startswith("GRUB_DISTRIBUTOR"):
+                lines[i] = distributor_line
+                have_distributor_line = True
+    else:
+        lines = []
+        if "defaults" in libcalamares.job.configuration:
+            for key, value in libcalamares.job.configuration["defaults"].items():
+                if value.__class__.__name__ == "bool":
+                    if value:
+                        escaped_value = "true"
+                    else:
+                        escaped_value = "false"
+                else:
+                    escaped_value = str(value).replace("'", "'\\''")
+                lines.append("%s='%s'" % (key, escaped_value))
+
+    if not have_kernel_cmd:
+        lines.append(kernel_cmd)
+
+    if not have_distributor_line:
+        lines.append(distributor_line)
 
     with open(default_grub, 'w') as grub_file:
         grub_file.write("\n".join(lines) + "\n")