diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
index 4c7c0194160d..79537c413939 100644
--- a/lib/matplotlib/backends/backend_qt5.py
+++ b/lib/matplotlib/backends/backend_qt5.py
@@ -240,7 +240,6 @@ def __init__(self, figure):
         self._dpi_ratio_prev = None
 
         self._draw_pending = False
-        self._erase_before_paint = False
         self._is_drawing = False
         self._draw_rect_callback = lambda painter: None
 
@@ -491,7 +490,6 @@ def draw(self):
             return
         with cbook._setattr_cm(self, _is_drawing=True):
             super().draw()
-        self._erase_before_paint = True
         self.update()
 
     def draw_idle(self):
diff --git a/lib/matplotlib/backends/backend_qt5agg.py b/lib/matplotlib/backends/backend_qt5agg.py
index ae37afe0bdbb..eadb0138fa5c 100644
--- a/lib/matplotlib/backends/backend_qt5agg.py
+++ b/lib/matplotlib/backends/backend_qt5agg.py
@@ -38,10 +38,6 @@ def paintEvent(self, event):
 
         painter = QtGui.QPainter(self)
 
-        if self._erase_before_paint:
-            painter.eraseRect(self.rect())
-            self._erase_before_paint = False
-
         rect = event.rect()
         left = rect.left()
         top = rect.top()
@@ -55,6 +51,10 @@ def paintEvent(self, event):
         reg = self.copy_from_bbox(bbox)
         buf = cbook._unmultiplied_rgba8888_to_premultiplied_argb32(
             memoryview(reg))
+
+        # clear the widget canvas
+        painter.eraseRect(rect)
+
         qimage = QtGui.QImage(buf, buf.shape[1], buf.shape[0],
                               QtGui.QImage.Format_ARGB32_Premultiplied)
         if hasattr(qimage, 'setDevicePixelRatio'):
diff --git a/lib/matplotlib/backends/backend_qt5cairo.py b/lib/matplotlib/backends/backend_qt5cairo.py
index bea4f6069c33..5a38a80864be 100644
--- a/lib/matplotlib/backends/backend_qt5cairo.py
+++ b/lib/matplotlib/backends/backend_qt5cairo.py
@@ -37,9 +37,7 @@ def paintEvent(self, event):
             # Not available on Qt4 or some older Qt5.
             qimage.setDevicePixelRatio(dpi_ratio)
         painter = QtGui.QPainter(self)
-        if self._erase_before_paint:
-            painter.eraseRect(self.rect())
-            self._erase_before_paint = False
+        painter.eraseRect(event.rect())
         painter.drawImage(0, 0, qimage)
         self._draw_rect_callback(painter)
         painter.end()