diff --git a/qutebrowser/misc/earlyinit.py b/qutebrowser/misc/earlyinit.py
index ca12cd901..5e8d4a1dd 100644
--- a/qutebrowser/misc/earlyinit.py
+++ b/qutebrowser/misc/earlyinit.py
@@ -230,8 +230,8 @@ def check_libraries():
     _check_modules(modules)
 
 
-def remove_inputhook():
-    """Remove the PyQt input hook.
+def configure_pyqt():
+    """Remove the PyQt input hook and enable overflow checking.
 
     Doing this means we can't use the interactive shell anymore (which we don't
     anyways), but we can use pdb instead.
@@ -239,6 +239,13 @@ def remove_inputhook():
     from PyQt5.QtCore import pyqtRemoveInputHook
     pyqtRemoveInputHook()
 
+    import sip
+    try:
+        # Added in sip 4.19.4
+        sip.enableoverflowchecking(True)
+    except AttributeError:
+        pass
+
 
 def init_log(args):
     """Initialize logging.
@@ -279,6 +286,6 @@ def early_init(args):
     # errors, so people only using the GUI notice them as well.
     check_libraries()
     check_qt_version()
-    remove_inputhook()
+    configure_pyqt()
     check_ssl_support()
     check_optimize_flag()