diff --git a/ssoauth/app_settings/__init__.py b/ssoauth/app_settings/__init__.py
index c30b676fbcbf612efcee1835005d576145b702ca..1b756823fc3594c7e612c754bc7c68ee1df41bd9 100644
--- a/ssoauth/app_settings/__init__.py
+++ b/ssoauth/app_settings/__init__.py
@@ -19,7 +19,7 @@ for setting_name in [k for k in globals().keys() if k.isupper()]:
 
 SSO_DISABLED = SSO_DISABLED or getattr(conf.settings, "IDP_IGNORE", False)  # legacy config
 if not SSO_DISABLED:
-    assert conf.settings.DEBUG, "Not ignoring IDP on production."
+    assert not conf.settings.DEBUG, "Not ignoring IDP on production."
     assert SP_HOST and SP_PORT, "Need SP_HOST and SP_PORT configured in settings."
     assert not SP_HOST.lower().startswith(("http:", "https:",)), "Need host name without protocol and port."