diff --git a/lib/python/pyflyby/_dbg.py b/lib/python/pyflyby/_dbg.py
index 1fe36ee0..96a6a0a3 100644
--- a/lib/python/pyflyby/_dbg.py
+++ b/lib/python/pyflyby/_dbg.py
@@ -335,7 +335,7 @@ def _debug_exception(*exc_info, **kwargs):
             # Check if the instance is of IPython's Pdb and its version.
             try:
                 import IPython
-                if IPython.__version__ >= '8.16':
+                if IPython.version_info >= (8, 16):
                     from IPython.core.debugger import Pdb as IPdb
                     # This is expected to be True, hence just a safe check.
                     if isinstance(pdb, IPdb):