diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
index 6cd226924764..ec2017d6d18c 100644
--- a/lib/matplotlib/backends/backend_qt5.py
+++ b/lib/matplotlib/backends/backend_qt5.py
@@ -132,7 +132,7 @@ def _create_qApp():
             # check for DISPLAY env variable on X11 build of Qt
             if hasattr(QtGui, "QX11Info"):
                 display = os.environ.get('DISPLAY')
-                if display is None or not re.search(':\d', display):
+                if display is None or not re.search(r':\d', display):
                     raise RuntimeError('Invalid DISPLAY variable')
 
             qApp = QtWidgets.QApplication([str(" ")])
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
index 0081f647c0f3..3a5db23424cb 100644
--- a/lib/matplotlib/pyplot.py
+++ b/lib/matplotlib/pyplot.py
@@ -2118,7 +2118,7 @@ def pad(s, l):
 
     commands = get_plot_commands()
 
-    first_sentence = re.compile("(?:\s*).+?\.(?:\s+|$)", flags=re.DOTALL)
+    first_sentence = re.compile(r"(?:\s*).+?\.(?:\s+|$)", flags=re.DOTALL)
 
     # Collect the first sentence of the docstring for all of the
     # plotting commands.