diff --git a/indra/llui/llfloater.cpp b/indra/llui/llfloater.cpp
index 720ff86aa7e53c3d62326852eeaa96b94605dcc4..da5dad6b82255b533d96b6e1f563345d3b0d6e52 100644
--- a/indra/llui/llfloater.cpp
+++ b/indra/llui/llfloater.cpp
@@ -1189,7 +1189,7 @@ void LLFloater::setFocus( BOOL b )
 			last_focus->setFocus(TRUE);
 		}
 	}
-	updateChildrenTransparency(this);
+	updateChildrenTransparency(this, b ? TT_ACTIVE : TT_INACTIVE);
 }
 
 // virtual
@@ -1768,13 +1768,11 @@ void	LLFloater::drawShadow(LLPanel* panel)
 		llround(shadow_offset));
 }
 
-void LLFloater::updateChildrenTransparency(LLView* ctrl)
+void LLFloater::updateChildrenTransparency(LLView* ctrl, ETypeTransparency transparency_type)
 {
 	child_list_t children = *ctrl->getChildList();
 	child_list_t::iterator it = children.begin();
 
-	ETypeTransparency transparency_type = hasFocus() ? TT_ACTIVE : TT_INACTIVE;
-
 	for(; it != children.end(); ++it)
 	{
 		LLUICtrl* ui_ctrl = dynamic_cast<LLUICtrl*>(*it);
@@ -1782,10 +1780,15 @@ void LLFloater::updateChildrenTransparency(LLView* ctrl)
 		{
 			ui_ctrl->setTransparencyType(transparency_type);
 		}
-		updateChildrenTransparency(*it);
+		updateChildrenTransparency(*it, transparency_type);
 	}
 }
 
+void LLFloater::updateChildrenTransparency(ETypeTransparency transparency_type)
+{
+	updateChildrenTransparency(this, transparency_type);
+}
+
 void	LLFloater::setCanMinimize(BOOL can_minimize)
 {
 	// if removing minimize/restore button programmatically,
diff --git a/indra/llui/llfloater.h b/indra/llui/llfloater.h
index e312702257f956bfa364b080b5b550f78678180f..2ec233f454b1ddad9c2ed322e783b134a37552ca 100644
--- a/indra/llui/llfloater.h
+++ b/indra/llui/llfloater.h
@@ -284,6 +284,8 @@ friend class LLMultiFloater;
 
 	static void		setFloaterHost(LLMultiFloater* hostp) {sHostp = hostp; }
 	static LLMultiFloater* getFloaterHost() {return sHostp; }
+
+	void			updateChildrenTransparency(ETypeTransparency transparency_type);
 		
 protected:
 
@@ -343,7 +345,7 @@ friend class LLMultiFloater;
 
 	static void		updateActiveFloaterTransparency();
 	static void		updateInactiveFloaterTransparency();
-	void			updateChildrenTransparency(LLView* ctrl);
+	void			updateChildrenTransparency(LLView* ctrl, ETypeTransparency transparency_type);
 
 public:
 	// Called when floater is opened, passes mKey
diff --git a/indra/newview/llsidetray.cpp b/indra/newview/llsidetray.cpp
index a4f855f2792e6acb36dd981e49db4ea4ef6df006..526f3d1e7720c963d73684b6bf34534826cd5092 100644
--- a/indra/newview/llsidetray.cpp
+++ b/indra/newview/llsidetray.cpp
@@ -118,7 +118,7 @@ class LLSideTrayTab: public LLPanel
 protected:
 	LLSideTrayTab(const Params& params);
 	
-	void			dock();
+	void			dock(LLFloater* floater_tab);
 	void			undock(LLFloater* floater_tab);
 
 	LLSideTray*		getSideTray();
@@ -259,7 +259,7 @@ void LLSideTrayTab::toggleTabDocked()
 
 	if (docking)
 	{
-		dock();
+		dock(floater_tab);
 	}
 	else
 	{
@@ -271,11 +271,14 @@ void LLSideTrayTab::toggleTabDocked()
 	LLFloaterReg::toggleInstance("side_bar_tab", tab_name);
 }
 
-void LLSideTrayTab::dock()
+void LLSideTrayTab::dock(LLFloater* floater_tab)
 {
 	LLSideTray* side_tray = getSideTray();
 	if (!side_tray) return;
 
+	// Before docking the tab, reset its (and its children's) transparency to default (STORM-688).
+	floater_tab->updateChildrenTransparency(TT_DEFAULT);
+
 	if (!side_tray->addTab(this))
 	{
 		llwarns << "Failed to add tab " << getName() << " to side tray" << llendl;