diff --git a/pyopencl/__init__.py b/pyopencl/__init__.py
index 15d1e2bb..fe1b4027 100644
--- a/pyopencl/__init__.py
+++ b/pyopencl/__init__.py
@@ -815,7 +815,6 @@ def kernel__setup(self, prg):
                 warn_about_arg_count_bug=None,
                 work_around_arg_count_bug=None, devs=self.context.devices)
 
-        self._wg_info_cache = {}
         return self
 
     def kernel_set_arg_types(self, arg_types):
@@ -856,14 +855,19 @@ def kernel_set_arg_types(self, arg_types):
                         devs=self.context.devices)
 
     def kernel_get_work_group_info(self, param, device):
+        try:
+            wg_info_cache = self._wg_info_cache
+        except AttributeError:
+            wg_info_cache = self._wg_info_cache = {}
+
         cache_key = (param, device.int_ptr)
         try:
-            return self._wg_info_cache[cache_key]
+            return wg_info_cache[cache_key]
         except KeyError:
             pass
 
         result = kernel_old_get_work_group_info(self, param, device)
-        self._wg_info_cache[cache_key] = result
+        wg_info_cache[cache_key] = result
         return result
 
     def kernel_set_args(self, *args, **kwargs):