diff --git a/setup.py b/setup.py
index e832160..1768907 100755
--- a/setup.py
+++ b/setup.py
@@ -45,7 +45,7 @@ def find_version(*file_paths):
     url='https://github.com/xyb/robotframework-debuglibrary/',
     keywords='robotframework,debug,shell,repl',
     install_requires=[
-        'prompt-toolkit < 3',  # 3.0 is not compatible with py3.5
+        'prompt-toolkit >= 2, < 3',  # 3.0 is not compatible with py3.5
         'robotframework >= 3.0',
     ],
     tests_require=['pexpect', 'coverage'],