diff --git a/src/b2/VBlankMonitorOSX.cpp b/src/b2/VBlankMonitorOSX.cpp
index d9e88882..0328dc4d 100644
--- a/src/b2/VBlankMonitorOSX.cpp
+++ b/src/b2/VBlankMonitorOSX.cpp
@@ -6,6 +6,7 @@
 #include "VBlankMonitor.h"
 #include <vector>
 #include "Messages.h"
+#include <inttypes.h>
 
 #include <shared/enum_def.h>
 #include "VBlankMonitorOSX_private.inl"
@@ -14,47 +15,35 @@
 //////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////
 
+LOG_TAGGED_DEFINE(VBLANK,"vblank","VBLANK",&log_printer_stderr_and_debugger)
+
+//////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////
+
 class VBlankMonitorOSX:
     public VBlankMonitor
 {
 public:
     ~VBlankMonitorOSX() {
+        CGDisplayRemoveReconfigurationCallback(&ReconfigurationCallback,this);
         this->ResetDisplaysList();
     }
     
     bool Init(Handler *handler,Messages *messages) override {
-        CVReturn cvr;
+        CGError cge;
 
         ASSERT(!m_handler);
         m_handler=handler;
-
+        
         if(!this->InitDisplaysList(messages)) {
             return false;
         }
         
-        for(auto &&display:m_displays) {
-            cvr=CVDisplayLinkCreateWithCGDisplay(display->id,
-                                                 &display->link);
-            if(cvr!=kCVReturnSuccess) {
-                messages->e.f("CVDisplayLinkCreateWithCGDisplay failed: %s\n",GetCVReturnEnumName(cvr));
-                return false;
-            }
-
-            cvr=CVDisplayLinkSetOutputCallback(display->link,
-                                               &OutputCallback,
-                                               display.get());
-            if(cvr!=kCVReturnSuccess) {
-                messages->e.f("CVDisplayLinkSetOutputCallback failed: %s\n",GetCVReturnEnumName(cvr));
-                return false;
-            }
-
-            cvr=CVDisplayLinkStart(display->link);
-            if(cvr!=kCVReturnSuccess) {
-                messages->e.f("CVDisplayLinkStart failed: %s\n",GetCVReturnEnumName(cvr));
-                return false;
-            }
+        cge=CGDisplayRegisterReconfigurationCallback(&ReconfigurationCallback,this);
+        if(cge!=kCGErrorSuccess) {
+            return false;
         }
-
+        
         return true;
     }
 
@@ -93,12 +82,30 @@ class VBlankMonitorOSX:
 protected:
 private:
     struct Display {
-        // CGDirectDisplayID=uint32_t
-        CGDirectDisplayID id=0;
+        CGDirectDisplayID const id;
+        VBlankMonitorOSX *const vbm;
+        
         CVDisplayLinkRef link=nullptr;
         void *data=nullptr;
-        VBlankMonitorOSX *vbm=nullptr;
-        std::atomic<bool> stop_thread{false};
+        
+        Display(CGDirectDisplayID id_,VBlankMonitorOSX *vbm_):
+        id(id_),
+        vbm(vbm_)
+        {
+        }
+        
+        ~Display() {
+            CVReturn cvr=CVDisplayLinkStop(this->link);
+            ASSERTF(cvr==kCVReturnSuccess,"%s",GetCVReturnEnumName(cvr));
+            this->link=nullptr;
+            
+            CVDisplayLinkRelease(this->link);
+            this->link=nullptr;
+            
+            if(this->data) {
+                this->vbm->m_handler->FreeDisplayData(this->id,this->data);
+            }
+        }
     };
     Handler *m_handler=nullptr;
     std::vector<std::unique_ptr<Display>> m_displays;
@@ -124,40 +131,79 @@ class VBlankMonitorOSX:
         }
 
         for(uint32_t i=0;i<num_cgdisplays;++i) {
-            auto &&display=std::make_unique<Display>();
-
-            display->id=cgdisplays[i];
-            display->vbm=this;
-
-            display->data=m_handler->AllocateDisplayData(display->id);
-            if(!display->data) {
-                messages->e.f("AllocateDisplayData failed\n");
-                return false;
+            if(!this->AddDisplay(cgdisplays[i])) {
+                // I have no idea how much help this error will be, but at least you'll know.
+                messages->e.f("Failed to initialise display 0x%" PRIx32 "\n",cgdisplays[i]);
             }
-
-            m_displays.push_back(std::move(display));
         }
 
         return true;
     }
 
     void ResetDisplaysList() {
+        while(!m_displays.empty()) {
+            this->RemoveDisplay(m_displays[0]->id);
+        }
+    }
+    
+    bool AddDisplay(CGDirectDisplayID id) {
+        CVReturn cvr;
+        
         for(auto &&display:m_displays) {
-            if(display->link) {
-                CVReturn cvr;
-
-                cvr=CVDisplayLinkStop(display->link);
-                ASSERTF(cvr==kCVReturnSuccess,"%s",GetCVReturnEnumName(cvr));
-
-                CVDisplayLinkRelease(display->link);
-                display->link=nullptr;
+            if(display->id==id) {
+                LOGF(VBLANK,"Add Display %" PRIx32 ": already added.\n",id);
+                return true;
             }
-
-            m_handler->FreeDisplayData(display->id,display->data);
-            display->data=nullptr;
         }
+        
+        auto &&display=std::make_unique<Display>(id,this);
 
-        m_displays.clear();
+        CGRect bounds=CGDisplayBounds(id);
+        (void)bounds;
+        LOGF(VBLANK,"Add Dispay %" PRIx32 ": ",id);
+        LOGI(VBLANK);
+        
+        LOGF(VBLANK,"(%.1f,%.1f), %.1f x %.1f\n",bounds.origin.x,bounds.origin.y,bounds.size.width,bounds.size.height);
+        
+        display->data=m_handler->AllocateDisplayData(display->id);
+        if(!display->data) {
+            LOGF(VBLANK,"AllocateDisplayData failed\n");
+            return false;
+        }
+        
+        cvr=CVDisplayLinkCreateWithCGDisplay(display->id,
+                                             &display->link);
+        if(cvr!=kCVReturnSuccess) {
+            LOGF(VBLANK,"CVDisplayLinkCreateWithCGDisplay failed: %s\n",GetCVReturnEnumName(cvr));
+            return false;
+        }
+            
+        cvr=CVDisplayLinkSetOutputCallback(display->link,
+                                           &OutputCallback,
+                                           display.get());
+        if(cvr!=kCVReturnSuccess) {
+            LOGF(VBLANK,"CVDisplayLinkSetOutputCallback failed: %s\n",GetCVReturnEnumName(cvr));
+            return false;
+        }
+        
+        cvr=CVDisplayLinkStart(display->link);
+        if(cvr!=kCVReturnSuccess) {
+            LOGF(VBLANK,"CVDisplayLinkStart failed: %s\n",GetCVReturnEnumName(cvr));
+            return false;
+        }
+        
+        m_displays.push_back(std::move(display));
+        return true;
+    }
+    
+    void RemoveDisplay(CGDirectDisplayID id) {
+        for(auto &&display_it=m_displays.begin();display_it!=m_displays.end();++display_it) {
+            if((*display_it)->id==id) {
+                LOGF(VBLANK,"Remove Display %" PRIx32 "\n",id);
+                m_displays.erase(display_it);
+                return;
+            }
+        }
     }
 
     static CVReturn OutputCallback(CVDisplayLinkRef displayLink,
@@ -177,6 +223,20 @@ class VBlankMonitorOSX:
 
         return kCVReturnSuccess;
     }
+    
+    static void ReconfigurationCallback(CGDirectDisplayID display,
+                                        CGDisplayChangeSummaryFlags flags,
+                                        void *userInfo)
+    {
+        auto vbm=(VBlankMonitorOSX *)userInfo;
+        
+        if(flags&kCGDisplayAddFlag) {
+            vbm->AddDisplay(display);
+        } else if(flags&kCGDisplayRemoveFlag) {
+            vbm->RemoveDisplay(display);
+        }
+    }
+                                        
 };
 
 //////////////////////////////////////////////////////////////////////////