diff --git a/gklearn/kernels/common_walk.py b/gklearn/kernels/common_walk.py
index f6ee71d..505dc18 100644
--- a/gklearn/kernels/common_walk.py
+++ b/gklearn/kernels/common_walk.py
@@ -75,9 +75,9 @@ class CommonWalk(GraphKernel):
 		# compute Gram matrix.
 		gram_matrix = np.zeros((len(self._graphs), len(self._graphs)))
 		
-		def init_worker(gn_toshare):
-			global G_gn
-			G_gn = gn_toshare
+# 		def init_worker(gn_toshare):
+# 			global G_gn
+# 			G_gn = gn_toshare
 			
 		# direct product graph method - exponential
 		if self.__compute_method == 'exp':
@@ -86,12 +86,17 @@ class CommonWalk(GraphKernel):
 		elif self.__compute_method == 'geo':
 			do_fun = self._wrapper_kernel_do_geo
 			
-		parallel_gm(do_fun, gram_matrix, self._graphs, init_worker=init_worker, 
-					glbv=(self._graphs,), n_jobs=self._n_jobs, verbose=self._verbose)
+		parallel_gm(do_fun, gram_matrix, self._graphs, init_worker=self._init_worker_gm, 
+			  glbv=(self._graphs,), n_jobs=self._n_jobs, verbose=self._verbose)
 			
 		return gram_matrix
 	
 	
+	def _init_worker_gm(gn_toshare):
+		global G_gn
+		G_gn = gn_toshare
+	
+	
 	def _compute_kernel_list_series(self, g1, g_list):
 		self.__check_graphs(g_list + [g1])
 		self.__add_dummy_labels(g_list + [g1])
@@ -130,10 +135,10 @@ class CommonWalk(GraphKernel):
 		# compute kernel list.
 		kernel_list = [None] * len(g_list)
 
-		def init_worker(g1_toshare, g_list_toshare):
-			global G_g1, G_g_list
-			G_g1 = g1_toshare
-			G_g_list = g_list_toshare
+# 		def init_worker(g1_toshare, g_list_toshare):
+# 			global G_g1, G_g_list
+# 			G_g1 = g1_toshare
+# 			G_g_list = g_list_toshare
 			
 		# direct product graph method - exponential
 		if self.__compute_method == 'exp':
@@ -147,12 +152,19 @@ class CommonWalk(GraphKernel):
 		itr = range(len(g_list))
 		len_itr = len(g_list)
 		parallel_me(do_fun, func_assign, kernel_list, itr, len_itr=len_itr,
-			init_worker=init_worker, glbv=(g1, g_list), method='imap_unordered', 
+			init_worker=self._init_worker_list, glbv=(g1, g_list), method='imap_unordered', 
 			n_jobs=self._n_jobs, itr_desc='calculating kernels', verbose=self._verbose)
 			
 		return kernel_list
 	
 	
+	def _init_worker_list(g1_toshare, g_list_toshare):
+		global G_g1, G_g_list
+		G_g1 = g1_toshare
+		G_g_list = g_list_toshare
+
+	
+	
 	def _wrapper_kernel_list_do_exp(self, itr):
 		return itr, self.__kernel_do_exp(G_g1, G_g_list[itr], self.__weight)