diff --git a/ChangeLog b/ChangeLog
index 1c9689741..ef14d901e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2014-01-19  Fred Kiefer <FredKiefer@gmx.de>
+
+	* Source/NSDocument.m: Add some NSError return values.
+
 2014-01-12  Fred Kiefer <FredKiefer@gmx.de>
 
 	* Source/NSTextAttachment.m: Add keyed coding.
diff --git a/Source/NSDocument.m b/Source/NSDocument.m
index c27adf41a..2f46ac46f 100644
--- a/Source/NSDocument.m
+++ b/Source/NSDocument.m
@@ -29,6 +29,7 @@
 */
 
 #import <Foundation/NSData.h>
+#import <Foundation/NSError.h>
 #import <Foundation/NSException.h>
 #import <Foundation/NSFileManager.h>
 #import <Foundation/NSNotification.h>
@@ -48,6 +49,16 @@
 
 #import "GSGuiPrivate.h"
 
+static inline NSError*
+create_error(int code, NSString* desc)
+{
+  return [NSError errorWithDomain: @"NSDocument"
+                  code: code 
+                  userInfo: [NSDictionary 
+                                dictionaryWithObjectsAndKeys: desc,
+                                NSLocalizedDescriptionKey, nil]];
+}
+
 @implementation NSDocument
 
 + (NSArray *) readableTypes
@@ -629,8 +640,11 @@ withContentsOfURL: (NSURL *)url
   data = [self dataOfType: type error: error];
   
   if (data == nil) 
-    return nil;
-
+    {
+      *error = create_error(0, NSLocalizedString(@"Could not create data for type.",
+                                                 @"Error description"));
+      return nil;
+    }
   return AUTORELEASE([[NSFileWrapper alloc] initRegularFileWithContents: data]);
 }
 
@@ -730,9 +744,11 @@ withContentsOfURL: (NSURL *)url
                           error: error];
     }
 
-  // FIXME: Set error
   if (error)
-    *error = nil;
+    {
+      *error = create_error(0, NSLocalizedString(@"File wrapper is no file.",
+                                                 @"Error description"));
+    }
   return NO;
 }
 
@@ -894,6 +910,11 @@ withContentsOfURL: (NSURL *)url
                  ofType: type 
                  saveOperation: op])
 	{
+          if (error)
+            {
+              *error = create_error(0, NSLocalizedString(@"Could not write backup file.",
+                                                         @"Error description"));
+            }
 	  return NO;
 	}
 
@@ -907,9 +928,11 @@ withContentsOfURL: (NSURL *)url
 
   if (!isNativeType || (url == nil))
     {
-      // FIXME: Set error
       if (error)
-	*error = nil; 
+        {
+          *error = create_error(0, NSLocalizedString(@"Not a writable type or no URL given.",
+                                                     @"Error description"));
+        }
       return NO;
     }
   
@@ -927,9 +950,11 @@ withContentsOfURL: (NSURL *)url
               if (![self _writeBackupForFile: fileName
                          toFile: backupFilename])
                 {
-                  // FIXME: Set error.
 		  if (error)
-		    *error = nil; 
+                    {
+                      *error = create_error(0, NSLocalizedString(@"Could not write backup file.",
+                                                                 @"Error description"));
+                    }
                   return NO;
                 }
             }
@@ -997,9 +1022,11 @@ withContentsOfURL: (NSURL *)url
                       error: error];
       if (wrapper == nil)
         {
-          // FIXME: Set error
 	  if (error)
-	    *error = nil; 
+            {
+              *error = create_error(0, NSLocalizedString(@"Could not write file wrapper.",
+                                                         @"Error description"));
+            }
           return NO;
         }