diff --git a/src/MacVim/MMBackend.h b/src/MacVim/MMBackend.h
index 733578af76..bbebc7e24e 100644
--- a/src/MacVim/MMBackend.h
+++ b/src/MacVim/MMBackend.h
@@ -105,6 +105,7 @@ extern NSTimeInterval MMBalloonEvalInternalDelay;
 - (BOOL)tabBarVisible;
 - (void)showTabBar:(BOOL)enable;
 - (void)setRows:(int)rows columns:(int)cols;
+- (void)resizeView;
 - (void)setWindowTitle:(char *)title;
 - (void)setDocumentFilename:(char *)filename;
 - (char *)browseForFileWithAttributes:(NSDictionary *)attr;
diff --git a/src/MacVim/MMBackend.m b/src/MacVim/MMBackend.m
index c56225a5f0..ce0d62f70b 100644
--- a/src/MacVim/MMBackend.m
+++ b/src/MacVim/MMBackend.m
@@ -836,6 +836,11 @@ - (void)setRows:(int)rows columns:(int)cols
     [self queueMessage:SetTextDimensionsMsgID data:data];
 }
 
+- (void)resizeView
+{
+    [self queueMessage:ResizeViewMsgID data:nil];
+}
+
 - (void)setWindowTitle:(char *)title
 {
     NSMutableData *data = [NSMutableData data];
@@ -1997,6 +2002,7 @@ - (void)handleInputEvent:(int)msgid data:(NSData *)data
 
         tabpage_move(idx);
     } else if (SetTextDimensionsMsgID == msgid || LiveResizeMsgID == msgid
+            || SetTextDimensionsNoResizeWindowMsgID == msgid
             || SetTextRowsMsgID == msgid || SetTextColumnsMsgID == msgid) {
         if (!data) return;
         const void *bytes = [data bytes];
@@ -2028,6 +2034,8 @@ - (void)handleInputEvent:(int)msgid data:(NSData *)data
         [self queueMessage:msgid data:d];
 
         gui_resize_shell(cols, rows);
+    } else if (ResizeViewMsgID == msgid) {
+        [self queueMessage:msgid data:data];
     } else if (ExecuteMenuMsgID == msgid) {
         NSDictionary *attrs = [NSDictionary dictionaryWithData:data];
         if (attrs) {
diff --git a/src/MacVim/MMVimController.m b/src/MacVim/MMVimController.m
index 66d4b4b556..600b55ca29 100644
--- a/src/MacVim/MMVimController.m
+++ b/src/MacVim/MMVimController.m
@@ -574,6 +574,7 @@ - (void)handleMessage:(int)msgid data:(NSData *)data
         [windowController showTabBar:NO];
         [self sendMessage:BackingPropertiesChangedMsgID data:nil];
     } else if (SetTextDimensionsMsgID == msgid || LiveResizeMsgID == msgid ||
+            SetTextDimensionsNoResizeWindowMsgID == msgid ||
             SetTextDimensionsReplyMsgID == msgid) {
         const void *bytes = [data bytes];
         int rows = *((int*)bytes);  bytes += sizeof(int);
@@ -583,11 +584,16 @@ - (void)handleMessage:(int)msgid data:(NSData *)data
         // acknowledges it with a reply message.  When this happens the window
         // should not move (the frontend would already have moved the window).
         BOOL onScreen = SetTextDimensionsReplyMsgID!=msgid;
+        
+        BOOL keepGUISize = SetTextDimensionsNoResizeWindowMsgID == msgid;
 
         [windowController setTextDimensionsWithRows:rows
                                  columns:cols
                                   isLive:(LiveResizeMsgID==msgid)
+                            keepGUISize:keepGUISize
                             keepOnScreen:onScreen];
+    } else if (ResizeViewMsgID == msgid) {
+        [windowController resizeView];
     } else if (SetWindowTitleMsgID == msgid) {
         const void *bytes = [data bytes];
         int len = *((int*)bytes);  bytes += sizeof(int);
diff --git a/src/MacVim/MMVimView.h b/src/MacVim/MMVimView.h
index 5a8335ed1e..8ecaa24b2c 100644
--- a/src/MacVim/MMVimView.h
+++ b/src/MacVim/MMVimView.h
@@ -55,6 +55,7 @@
 - (void)viewWillStartLiveResize;
 - (void)viewDidEndLiveResize;
 - (void)setFrameSize:(NSSize)size;
+- (void)setFrameSizeKeepGUISize:(NSSize)size;
 - (void)setFrame:(NSRect)frame;
 
 @end
diff --git a/src/MacVim/MMVimView.m b/src/MacVim/MMVimView.m
index fd04c47e5b..6202a186f3 100644
--- a/src/MacVim/MMVimView.m
+++ b/src/MacVim/MMVimView.m
@@ -60,7 +60,7 @@ - (MMScroller *)scrollbarForIdentifier:(int32_t)ident index:(unsigned *)idx;
 - (NSSize)vimViewSizeForTextViewSize:(NSSize)textViewSize;
 - (NSRect)textViewRectForVimViewSize:(NSSize)contentSize;
 - (NSTabView *)tabView;
-- (void)frameSizeMayHaveChanged;
+- (void)frameSizeMayHaveChanged:(BOOL)keepGUISize;
 @end
 
 
@@ -610,14 +610,25 @@ - (void)setFrameSize:(NSSize)size
     // row will result in the vim view holding more rows than the can fit
     // inside the window.)
     [super setFrameSize:size];
-    [self frameSizeMayHaveChanged];
+    [self frameSizeMayHaveChanged:NO];
+}
+
+- (void)setFrameSizeKeepGUISize:(NSSize)size
+{
+    // NOTE: Instead of only acting when a frame was resized, we do some
+    // updating each time a frame may be resized.  (At the moment, if we only
+    // respond to actual frame changes then typing ":set lines=1000" twice in a
+    // row will result in the vim view holding more rows than the can fit
+    // inside the window.)
+    [super setFrameSize:size];
+    [self frameSizeMayHaveChanged:YES];
 }
 
 - (void)setFrame:(NSRect)frame
 {
     // See comment in setFrameSize: above.
     [super setFrame:frame];
-    [self frameSizeMayHaveChanged];
+    [self frameSizeMayHaveChanged:NO];
 }
 
 @end // MMVimView
@@ -867,7 +878,7 @@ - (NSTabView *)tabView
     return tabView;
 }
 
-- (void)frameSizeMayHaveChanged
+- (void)frameSizeMayHaveChanged:(BOOL)keepGUISize
 {
     // NOTE: Whenever a call is made that may have changed the frame size we
     // take the opportunity to make sure all subviews are in place and that the
@@ -903,7 +914,7 @@ - (void)frameSizeMayHaveChanged
     if (constrained[0] != rows || constrained[1] != cols) {
         NSData *data = [NSData dataWithBytes:constrained length:2*sizeof(int)];
         int msgid = [self inLiveResize] ? LiveResizeMsgID
-                                        : SetTextDimensionsMsgID;
+                                        : (keepGUISize ? SetTextDimensionsNoResizeWindowMsgID : SetTextDimensionsMsgID);
 
         ASLogDebug(@"Notify Vim that text dimensions changed from %dx%d to "
                    "%dx%d (%s)", cols, rows, constrained[1], constrained[0],
diff --git a/src/MacVim/MMWindowController.h b/src/MacVim/MMWindowController.h
index 8c92ed537d..5e97478f9a 100644
--- a/src/MacVim/MMWindowController.h
+++ b/src/MacVim/MMWindowController.h
@@ -24,6 +24,7 @@
     BOOL                setupDone;
     BOOL                windowPresented;
     BOOL                shouldResizeVimView;
+    BOOL                shouldKeepGUISize;
     BOOL                shouldRestoreUserTopLeft;
     BOOL                shouldMaximizeWindow;
     int                 updateToolbarFlag;
@@ -59,7 +60,9 @@
 - (void)updateTabsWithData:(NSData *)data;
 - (void)selectTabWithIndex:(int)idx;
 - (void)setTextDimensionsWithRows:(int)rows columns:(int)cols isLive:(BOOL)live
+                      keepGUISize:(BOOL)keepGUISize
                      keepOnScreen:(BOOL)onScreen;
+- (void)resizeView;
 - (void)zoomWithRows:(int)rows columns:(int)cols state:(int)state;
 - (void)setTitle:(NSString *)title;
 - (void)setDocumentFilename:(NSString *)filename;
diff --git a/src/MacVim/MMWindowController.m b/src/MacVim/MMWindowController.m
index 5f7ddbf30a..c6fa99d795 100644
--- a/src/MacVim/MMWindowController.m
+++ b/src/MacVim/MMWindowController.m
@@ -174,7 +174,7 @@ - (id)initWithVimController:(MMVimController *)controller
 
     [win setDelegate:self];
     [win setInitialFirstResponder:[vimView textView]];
-    
+
     if ([win styleMask] & NSWindowStyleMaskTexturedBackground) {
         // On Leopard, we want to have a textured window to have nice
         // looking tabs. But the textured window look implies rounded
@@ -381,6 +381,7 @@ - (void)selectTabWithIndex:(int)idx
 }
 
 - (void)setTextDimensionsWithRows:(int)rows columns:(int)cols isLive:(BOOL)live
+                      keepGUISize:(BOOL)keepGUISize
                      keepOnScreen:(BOOL)onScreen
 {
     ASLogDebug(@"setTextDimensionsWithRows:%d columns:%d isLive:%d "
@@ -399,7 +400,7 @@ - (void)setTextDimensionsWithRows:(int)rows columns:(int)cols isLive:(BOOL)live
 
     [vimView setDesiredRows:rows columns:cols];
 
-    if (setupDone && !live) {
+    if (setupDone && !live && !keepGUISize) {
         shouldResizeVimView = YES;
         keepOnScreen = onScreen;
     }
@@ -428,6 +429,15 @@ - (void)setTextDimensionsWithRows:(int)rows columns:(int)cols isLive:(BOOL)live
     }
 }
 
+- (void)resizeView
+{
+    if (setupDone)
+    {
+        shouldResizeVimView = YES;
+        shouldKeepGUISize = YES;
+    }
+}
+
 - (void)zoomWithRows:(int)rows columns:(int)cols state:(int)state
 {
     [self setTextDimensionsWithRows:rows
@@ -503,9 +513,6 @@ - (void)createScrollbarWithIdentifier:(int32_t)ident type:(int)type
 - (BOOL)destroyScrollbarWithIdentifier:(int32_t)ident
 {
     BOOL scrollbarHidden = [vimView destroyScrollbarWithIdentifier:ident];   
-    shouldResizeVimView = shouldResizeVimView || scrollbarHidden;
-    shouldMaximizeWindow = shouldMaximizeWindow || scrollbarHidden;
-
     return scrollbarHidden;
 }
 
@@ -513,9 +520,6 @@ - (BOOL)showScrollbarWithIdentifier:(int32_t)ident state:(BOOL)visible
 {
     BOOL scrollbarToggled = [vimView showScrollbarWithIdentifier:ident
                                                            state:visible];
-    shouldResizeVimView = shouldResizeVimView || scrollbarToggled;
-    shouldMaximizeWindow = shouldMaximizeWindow || scrollbarToggled;
-
     return scrollbarToggled;
 }
 
@@ -600,7 +604,18 @@ - (void)processInputQueueDidFinish
                                   fullScreenWindow ? [fullScreenWindow frame].size :
                                   fullScreenEnabled ? desiredWindowSize :
                                   [self constrainContentSizeToScreenSize:[vimView desiredSize]]];
-            [vimView setFrameSize:contentSize];
+
+            // Setting 'guioptions+=k' will make shouldKeepGUISize true, which
+            // means avoid resizing the window. Instead, resize the view instead
+            // to keep the GUI window's size consistent.
+            bool avoidWindowResize = shouldKeepGUISize && !fullScreenEnabled;
+
+            if (!avoidWindowResize) {
+                [vimView setFrameSize:contentSize];
+            }
+            else {
+                [vimView setFrameSizeKeepGUISize:originalSize];
+            }
 
             if (fullScreenWindow) {
                 // NOTE! Don't mark the full-screen content view as needing an
@@ -613,12 +628,15 @@ - (void)processInputQueueDidFinish
                     [fullScreenWindow centerView];
                 }
             } else {
-                [self resizeWindowToFitContentSize:contentSize
-                                      keepOnScreen:keepOnScreen];
+                if (!avoidWindowResize) {
+                    [self resizeWindowToFitContentSize:contentSize
+                                          keepOnScreen:keepOnScreen];
+                }
             }
         }
 
         keepOnScreen = NO;
+        shouldKeepGUISize = NO;
     }
 }
 
@@ -657,7 +675,6 @@ - (void)adjustLinespace:(int)linespace
 {
     if (vimView && [vimView textView]) {
         [[vimView textView] setLinespace:(float)linespace];
-        shouldMaximizeWindow = shouldResizeVimView = YES;
     }
 }
 
@@ -665,7 +682,6 @@ - (void)adjustColumnspace:(int)columnspace
 {
     if (vimView && [vimView textView]) {
         [[vimView textView] setColumnspace:(float)columnspace];
-        shouldMaximizeWindow = shouldResizeVimView = YES;
     }
 }
 
@@ -1177,7 +1193,7 @@ - (void)window:(NSWindow *)window
             [[window animator] setAlphaValue:0];
         } completionHandler:^{
             [self maximizeWindow:fullScreenOptions];
-            
+
             // Fade in
             [NSAnimationContext runAnimationGroup:^(NSAnimationContext *context) {
                 [context setDuration:0.5*duration];
@@ -1196,7 +1212,7 @@ - (void)windowWillEnterFullScreen:(NSNotification *)notification
 
     // The separator should never be visible in fullscreen or split-screen.
     [decoratedWindow hideTablineSeparator:YES];
-  
+
     // ASSUMPTION: fullScreenEnabled always reflects the state of Vim's 'fu'.
     if (!fullScreenEnabled) {
         ASLogDebug(@"Full-screen out of sync, tell Vim to set 'fu'");
@@ -1298,7 +1314,7 @@ - (void)windowDidExitFullScreen:(NSNotification *)notification
         // full-screen by moving the window out from Split View.
         [vimController sendMessage:BackingPropertiesChangedMsgID data:nil];
     }
-  
+
     [self updateTablineSeparator];
 }
 
@@ -1519,7 +1535,6 @@ - (void)hideTablineSeparator:(BOOL)hide
         // The tabline separator was toggled so the content view must change
         // size.
         [self updateResizeConstraints];
-        shouldResizeVimView = YES;
     }
 }
 
diff --git a/src/MacVim/MacVim.h b/src/MacVim/MacVim.h
index 2a8a53f588..ad09586ed1 100644
--- a/src/MacVim/MacVim.h
+++ b/src/MacVim/MacVim.h
@@ -176,8 +176,10 @@ enum {
     SetTextRowsMsgID,
     SetTextColumnsMsgID,
     SetTextDimensionsMsgID,
+    SetTextDimensionsNoResizeWindowMsgID,
     LiveResizeMsgID,
     SetTextDimensionsReplyMsgID,
+    ResizeViewMsgID,
     SetWindowTitleMsgID,
     ScrollWheelMsgID,
     MouseDownMsgID,
diff --git a/src/MacVim/MacVim.m b/src/MacVim/MacVim.m
index b9fdeb43c9..6390a29139 100644
--- a/src/MacVim/MacVim.m
+++ b/src/MacVim/MacVim.m
@@ -30,8 +30,10 @@
     "SetTextRowsMsgID",
     "SetTextColumnsMsgID",
     "SetTextDimensionsMsgID",
+    "SetTextDimensionsNoResizeWindowMsgID",
     "LiveResizeMsgID",
     "SetTextDimensionsReplyMsgID",
+    "ResizeViewMsgID",
     "SetWindowTitleMsgID",
     "ScrollWheelMsgID",
     "MouseDownMsgID",
diff --git a/src/MacVim/gui_macvim.m b/src/MacVim/gui_macvim.m
index d6fa0a0929..ed1e9c4168 100644
--- a/src/MacVim/gui_macvim.m
+++ b/src/MacVim/gui_macvim.m
@@ -1732,6 +1732,18 @@
 }
 
 
+/*
+ * Re-calculates size of the Vim view to fit within the window without having
+ * to resize the window. Usually happens after UI elements have changed (e.g.
+ * adding / removing a toolbar) when guioptions 'k' is set.
+ */
+    void
+gui_mch_resize_view()
+{
+    [[MMBackend sharedInstance] resizeView];
+}
+
+
 /*
  * Set the position of the top left corner of the window to the given
  * coordinates.
diff --git a/src/gui.c b/src/gui.c
index 6b1ce1c968..14262ab7ee 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -1621,6 +1621,16 @@ gui_set_shellsize(
     }
 #endif
 
+#ifdef FEAT_GUI_MACVIM
+    if (!mustset && (vim_strchr(p_go, GO_KEEPWINSIZE) != NULL))
+    {
+	/* We don't want to resize the window, so instruct the GUI to resize
+	 * the view to be within the constraints of the current window's size */
+	gui_mch_resize_view();
+	return;
+    }
+#endif
+
     base_width = gui_get_base_width();
     base_height = gui_get_base_height();
     if (fit_to_display)
diff --git a/src/proto/gui_macvim.pro b/src/proto/gui_macvim.pro
index dd75a6f2b3..8fdab4ef70 100644
--- a/src/proto/gui_macvim.pro
+++ b/src/proto/gui_macvim.pro
@@ -174,6 +174,8 @@ gui_mch_set_shellsize(
     int		base_height,
     int		direction);
     void
+gui_mch_resize_view();
+    void
 gui_mch_set_sp_color(guicolor_T color);
     void
 gui_mch_set_text_area_pos(int x, int y, int w, int h);