--- a/testing/geckodriver/doc/CrashReports.md
+++ b/testing/geckodriver/doc/CrashReports.md
@@ -10,16 +10,18 @@ Retrieve the crash data
 -----------------------
 
 Because geckodriver creates a temporary user profile for Firefox, it also
 automatically removes all its folders once the tests have been finished. That
 also means that if Firefox crashed the created minidump files are lost. To
 prevent that a custom profile has to be used instead. The following code
 shows an example by using the Python Selenium bindings on Mac OS:
 
+    import tempfile
+
     from selenium import webdriver
     from selenium.webdriver.firefox.options import Options
 
     # Custom profile folder to keep the minidump files
     profile = tempfile.mkdtemp(".selenium")
     print("*** Using profile: {}".format(profile))
 
     # Use the above folder as custom profile