diff --git a/pyopencl/cffi_cl.py b/pyopencl/cffi_cl.py
index a7c7d2a53e385dd073474365ee14a556628db028..826fd03642e7ca4fbfec47e198ad3c554e16584f 100644
--- a/pyopencl/cffi_cl.py
+++ b/pyopencl/cffi_cl.py
@@ -338,7 +338,7 @@ class device_type(_ConstantsNamespace):  # noqa
                 continue
             if not name.startswith("_"):
                 bitfield = getattr(cls, name)
-                if ((bitfield & value) == bitfield):
+                if isinstance(bitfield, int) and ((bitfield & value) == bitfield):
                     return name
 
         if default_format is None: