diff --git a/modules/desktop_capture/mac/screen_capturer_mac.mm b/modules/desktop_capture/mac/screen_capturer_mac.mm
index 542d1c5f43..9f506732a6 100644
--- a/modules/desktop_capture/mac/screen_capturer_mac.mm
+++ b/modules/desktop_capture/mac/screen_capturer_mac.mm
@@ -218,6 +218,17 @@ void ScreenCapturerMac::CaptureFrame() {
     ScreenConfigurationChanged();
   }
 
+  // When screen is zoomed in/out, OSX only updates the part of Rects currently
+  // displayed on screen, with relative location to current top-left on screen.
+  // This will cause problems when we copy the dirty regions to the captured
+  // image. So we invalidate the whole screen to copy all the screen contents.
+  // With CGI method, the zooming will be ignored and the whole screen contents
+  // will be captured as before.
+  // With IOSurface method, the zoomed screen contents will be captured.
+  if (UAZoomEnabled()) {
+    helper_.InvalidateScreen(screen_pixel_bounds_.size());
+  }
+
   DesktopRegion region;
   helper_.TakeInvalidRegion(&region);
 
@@ -285,10 +296,9 @@ bool ScreenCapturerMac::SelectSource(SourceId id) {
 }
 
 bool ScreenCapturerMac::CgBlit(const DesktopFrame& frame, const DesktopRegion& region) {
-  // Copy the entire contents of the previous capture buffer, to capture over.
-  // TODO(wez): Get rid of this as per crbug.com/145064, or implement
-  // crbug.com/92354.
-  if (queue_.previous_frame()) {
+  // If not all screen region is dirty, copy the entire contents of the previous capture buffer,
+  // to capture over.
+  if (queue_.previous_frame() && !region.Equals(DesktopRegion(screen_pixel_bounds_))) {
     memcpy(frame.data(), queue_.previous_frame()->data(), frame.stride() * frame.size().height());
   }