diff --git a/qtpy/__init__.py b/qtpy/__init__.py
index 31175bd8..71ec168c 100644
--- a/qtpy/__init__.py
+++ b/qtpy/__init__.py
@@ -116,7 +116,7 @@ class PythonQtWarning(Warning):
 
 # When `FORCE_QT_API` is set, we disregard
 # any previously imported python bindings.
-if os.environ.get('FORCE_QT_API') is not None:
+if not os.environ.get('FORCE_QT_API'):
     if 'PyQt5' in sys.modules:
         API = initial_api if initial_api in PYQT5_API else 'pyqt5'
     elif 'PySide2' in sys.modules: