diff --git a/src/apps/showimage/ShowImageView.cpp b/src/apps/showimage/ShowImageView.cpp
index 1a0faa431f..efc58ef7d2 100644
--- a/src/apps/showimage/ShowImageView.cpp
+++ b/src/apps/showimage/ShowImageView.cpp
@@ -186,6 +186,7 @@ ShowImageView::ShowImageView(BRect rect, const char* name, uint32 resizingMode,
 	fBitmapLocationInView(0.0, 0.0),
 
 	fStretchToBounds(false),
+	fForceOriginalSize(false),
 	fHideCursor(false),
 	fScrollingBitmap(false),
 	fCreatingSelection(false),
@@ -1630,7 +1631,7 @@ ShowImageView::FitToBounds()
 		return;
 
 	float fitToBoundsZoom = _FitToBoundsZoom();
-	if (!fStretchToBounds && fitToBoundsZoom > 1.0f)
+	if (!fStretchToBounds && fitToBoundsZoom > 1.0f || fForceOriginalSize)
 		SetZoom(1.0f);
 	else
 		SetZoom(fitToBoundsZoom);
diff --git a/src/apps/showimage/ShowImageView.h b/src/apps/showimage/ShowImageView.h
index 33f312770e..a0d207e240 100644
--- a/src/apps/showimage/ShowImageView.h
+++ b/src/apps/showimage/ShowImageView.h
@@ -87,6 +87,8 @@ public:
 			void				CopySelectionToClipboard();
 
 			void				FitToBounds();
+			void				ForceOriginalSize(bool force)
+									{ fForceOriginalSize = force; }
 			void				SetZoom(float zoom,
 									BPoint where = BPoint(-1, -1));
 			float				Zoom() const
@@ -194,6 +196,7 @@ private:
 			BPoint				fBitmapLocationInView;
 
 			bool				fStretchToBounds;
+			bool				fForceOriginalSize;
 			bool				fHideCursor;
 			bool				fScrollingBitmap;
 			bool				fCreatingSelection;
diff --git a/src/apps/showimage/ShowImageWindow.cpp b/src/apps/showimage/ShowImageWindow.cpp
index ca7b5a30ff..46efa71ff6 100644
--- a/src/apps/showimage/ShowImageWindow.cpp
+++ b/src/apps/showimage/ShowImageWindow.cpp
@@ -25,6 +25,7 @@
 #include <Application.h>
 #include <Bitmap.h>
 #include <BitmapStream.h>
+#include <Button.h>
 #include <Catalog.h>
 #include <Clipboard.h>
 #include <Entry.h>
@@ -176,29 +177,31 @@ ShowImageWindow::ShowImageWindow(BRect frame, const entry_ref& ref,
 //	fToolBarView->AddAction(MSG_FILE_OPEN, be_app,
 //		tool_bar_icon(kIconDocumentOpen), B_TRANSLATE("Open"B_UTF8_ELLIPSIS));
 	fToolBarView->AddAction(MSG_FILE_PREV, this,
-		tool_bar_icon(kIconGoPrevious), B_TRANSLATE("Previous file"));
+		tool_bar_icon(kIconGoPrevious), B_TRANSLATE("Previous file"), false);
 	fToolBarView->AddAction(MSG_FILE_NEXT, this, tool_bar_icon(kIconGoNext),
-		B_TRANSLATE("Next file"));
+		B_TRANSLATE("Next file"), false);
 	BMessage* fullScreenSlideShow = new BMessage(MSG_SLIDE_SHOW);
 	fullScreenSlideShow->AddBool("full screen", true);
 	fToolBarView->AddAction(fullScreenSlideShow, this,
-		tool_bar_icon(kIconMediaMovieLibrary), B_TRANSLATE("Slide show"));
+		tool_bar_icon(kIconMediaMovieLibrary), B_TRANSLATE("Slide show"),
+		false);
 	fToolBarView->AddSeparator();
 	fToolBarView->AddAction(MSG_SELECTION_MODE, this,
 		tool_bar_icon(kIconDrawRectangularSelection),
-		B_TRANSLATE("Selection mode"));
+		B_TRANSLATE("Selection mode"), false);
 	fToolBarView->AddSeparator();
 	fToolBarView->AddAction(kMsgOriginalSize, this,
-		tool_bar_icon(kIconZoomOriginal), B_TRANSLATE("Original size"));
+		tool_bar_icon(kIconZoomOriginal), B_TRANSLATE("Original size"), true);
 	fToolBarView->AddAction(kMsgFitToWindow, this,
-		tool_bar_icon(kIconZoomFitBest), B_TRANSLATE("Fit to window"));
+		tool_bar_icon(kIconZoomFitBest), B_TRANSLATE("Fit to window"), false);
 	fToolBarView->AddAction(MSG_ZOOM_IN, this, tool_bar_icon(kIconZoomIn),
-		B_TRANSLATE("Zoom in"));
+		B_TRANSLATE("Zoom in"), false);
 	fToolBarView->AddAction(MSG_ZOOM_OUT, this, tool_bar_icon(kIconZoomOut),
-		B_TRANSLATE("Zoom out"));
+		B_TRANSLATE("Zoom out"), false);
 	fToolBarView->AddGlue();
 	fToolBarView->AddAction(MSG_FULL_SCREEN, this,
-		tool_bar_icon(kIconViewWindowed), B_TRANSLATE("Leave full screen"));
+		tool_bar_icon(kIconViewWindowed), B_TRANSLATE("Leave full screen"),
+		false);
 	fToolBarView->SetActionVisible(MSG_FULL_SCREEN, false);
 
 	fToolBarView->ResizeTo(viewFrame.Width(), fToolBarView->MinSize().height);
@@ -966,6 +969,13 @@ ShowImageWindow::MessageReceived(BMessage* message)
 			break;
 
 		case kMsgOriginalSize:
+			if (message->FindInt32("behavior") == BButton::B_TOGGLE_BEHAVIOR)
+			{
+				bool force = message->FindInt32("be:value");
+				fImageView->ForceOriginalSize(force);
+				if (!force)
+					break;
+			}
 			fImageView->SetZoom(1.0);
 			break;
 
diff --git a/src/apps/showimage/ToolBarView.cpp b/src/apps/showimage/ToolBarView.cpp
index 3c154080dc..58c37f270a 100644
--- a/src/apps/showimage/ToolBarView.cpp
+++ b/src/apps/showimage/ToolBarView.cpp
@@ -10,6 +10,34 @@
 #include <SeparatorView.h>
 #include <SpaceLayoutItem.h>
 
+class LockableButton: public BButton
+{
+public:
+	LockableButton(const char* name, const char* label, BMessage* message);
+
+	void MouseDown(BPoint point);
+};
+
+
+LockableButton::LockableButton(const char* name, const char* label,
+	BMessage* message)
+	: BButton(name, label, message)
+{
+}
+
+
+void
+LockableButton::MouseDown(BPoint point)
+{
+	if (modifiers() & B_SHIFT_KEY || Value() == B_CONTROL_ON)
+		SetBehavior(B_TOGGLE_BEHAVIOR);
+	else
+		SetBehavior(B_BUTTON_BEHAVIOR);
+
+	Message()->SetInt32("behavior", Behavior());
+	BButton::MouseDown(point);
+}
+
 
 ToolBarView::ToolBarView(BRect frame)
 	:
@@ -44,17 +72,22 @@ ToolBarView::Hide()
 
 void
 ToolBarView::AddAction(uint32 command, BHandler* target, const BBitmap* icon,
-	const char* toolTipText)
+	const char* toolTipText, bool lockable)
 {
-	AddAction(new BMessage(command), target, icon, toolTipText);
+	AddAction(new BMessage(command), target, icon, toolTipText, lockable);
 }
 
 
 void
 ToolBarView::AddAction(BMessage* message, BHandler* target,
-	const BBitmap* icon, const char* toolTipText)
+	const BBitmap* icon, const char* toolTipText, bool lockable)
 {
-	BButton* button = new BButton(NULL, NULL, message);
+
+	BButton* button;
+	if (lockable)
+		button = new LockableButton(NULL, NULL, message);
+	else
+		button = new BButton(NULL, NULL, message);
 	button->SetIcon(icon);
 	button->SetFlat(true);
 	if (toolTipText != NULL)
diff --git a/src/apps/showimage/ToolBarView.h b/src/apps/showimage/ToolBarView.h
index 63c6f0b202..6273d33713 100644
--- a/src/apps/showimage/ToolBarView.h
+++ b/src/apps/showimage/ToolBarView.h
@@ -20,10 +20,12 @@ public:
 
 			void				AddAction(uint32 command, BHandler* target,
 									const BBitmap* icon,
-									const char* toolTipText = NULL);
+									const char* toolTipText = NULL,
+									bool lockable = false);
 			void				AddAction(BMessage* message, BHandler* target,
 									const BBitmap* icon,
-									const char* toolTipText = NULL);
+									const char* toolTipText = NULL,
+									bool lockable = false);
 			void				AddSeparator();
 			void				AddGlue();