diff --git a/IPython/core/tests/test_debugger.py b/IPython/core/tests/test_debugger.py
index 0c479ab..fc81b71 100644
--- a/IPython/core/tests/test_debugger.py
+++ b/IPython/core/tests/test_debugger.py
@@ -369,6 +369,7 @@ def _decorator_skip_setup():
 
     env = os.environ.copy()
     env["IPY_TEST_SIMPLE_PROMPT"] = "1"
+    env["PROMPT_TOOLKIT_NO_CPR"] = "1"
 
     child = pexpect.spawn(
         sys.executable, ["-m", "IPython", "--colors=nocolor"], env=env