diff --git a/TodoTxtMac/TTMAppController.h b/TodoTxtMac/TTMAppController.h
old mode 100644
new mode 100755
index 1a9208f..fa699ae
--- a/TodoTxtMac/TTMAppController.h
+++ b/TodoTxtMac/TTMAppController.h
@@ -94,6 +94,21 @@ extern NSString *const TodoFileArgument;
  */
 - (NSString*)commandLineArgumentTodoFile;
 
+/*!
+ * @method openDoneFileFromCommandLineArgument:
+ * @abstract This method opens a done.txt file based on the command line argument.
+ * The name of the argument is defined in the DoneFileArgument constant.
+ * If there is no command line argument, this method does nothing.
+ */
+- (void)openDoneFileFromCommandLineArgument;
+
+/*!
+ * @method commandLineArgumentDoneFile:
+ * @abstract This method returns the value of the done-file command line argument.
+ * If there is no command-line argument, it returns null.
+ */
+- (NSString*)commandLineArgumentDoneFile;
+
 /*!
  * @method openDocumentFromFilePath:
  * @abstract This method opens a todo.txt file (TTMDocument) based on a file path.
diff --git a/TodoTxtMac/TTMAppController.m b/TodoTxtMac/TTMAppController.m
old mode 100644
new mode 100755
index b79ceea..60bfc02
--- a/TodoTxtMac/TTMAppController.m
+++ b/TodoTxtMac/TTMAppController.m
@@ -129,6 +129,7 @@ @implementation TTMAppController
 
 // Constants for command-line argument names
 NSString *const TodoFileArgument = @"todo-file";
+NSString *const DoneFileArgument = @"done-file";
 
 - (id)init {
     self = [super init];
@@ -195,11 +196,24 @@ - (void)openTodoFileFromCommandLineArgument {
     [self openDocumentFromFilePath:fileToOpenOnLaunch];
 }
 
+- (void)openDoneFileFromCommandLineArgument {
+    NSString *fileToOpenOnLaunch = [self commandLineArgumentDoneFile];
+    if (!fileToOpenOnLaunch) {
+        return;
+    }
+    [self openDocumentFromFilePath:fileToOpenOnLaunch];
+}
+
 - (NSString*)commandLineArgumentTodoFile {
     NSUserDefaults *args = [NSUserDefaults standardUserDefaults];
     return [args stringForKey:TodoFileArgument];
 }
 
+- (NSString*)commandLineArgumentDoneFile {
+    NSUserDefaults *args = [NSUserDefaults standardUserDefaults];
+    return [args stringForKey:DoneFileArgument];
+}
+
 - (void)openDocumentFromFilePath:(NSString*)filePath {
     NSURL *fileURL = [NSURL fileURLWithPath:filePath];
     [self openDocumentFromFileURL:fileURL];
diff --git a/TodoTxtMac/TTMAppDelegate.m b/TodoTxtMac/TTMAppDelegate.m
old mode 100644
new mode 100755
index e799c2e..0afe2ff
--- a/TodoTxtMac/TTMAppDelegate.m
+++ b/TodoTxtMac/TTMAppDelegate.m
@@ -53,9 +53,12 @@ @implementation TTMAppDelegate
 - (void)applicationDidFinishLaunching:(NSNotification *)notification {
     [self.appController initializeUserDefaults:self];
     
-    // Open file from command line argument. Does nothing if there is no command line argument.
+    // Open todo file from command line argument. Does nothing if there is no command line argument.
     [self.appController openTodoFileFromCommandLineArgument];
     
+    // Open done file from command line argument. Does nothing if there is no command line argument.
+    [self.appController openDoneFileFromCommandLineArgument];
+
     // Open default todo file, if one is selected and the option is enabled.
     [self.appController openDefaultTodoFile];
 }
@@ -67,6 +70,7 @@ - (BOOL)applicationShouldOpenUntitledFile:(NSApplication *)sender {
     // Without this method override, opening a todo file using the command line argument
     // or the default todo file user preference also opens an Untitled document every time.
     return ([self.appController commandLineArgumentTodoFile] == NULL &&
+            [self.appController commandLineArgumentDoneFile] == NULL &&
             ![[NSUserDefaults standardUserDefaults] boolForKey:@"openDefaultTodoFileOnStartup"]);
 }