diff --git a/src/sakia/core/graph/explorer_graph.py b/src/sakia/core/graph/explorer_graph.py
index a698e464..a34898db 100644
--- a/src/sakia/core/graph/explorer_graph.py
+++ b/src/sakia/core/graph/explorer_graph.py
@@ -85,12 +85,16 @@ async def _explore(self, identity, steps):
 
                     certifier_list, certified_list = await asyncio.gather(certifier_coro, certified_coro)
 
-                    await self.add_certifier_list(certifier_list, current_identity, identity)
+                    certifier_coro = asyncio.ensure_future(self.add_certifier_list(certifier_list,
+                                                                                   current_identity, identity))
                     logging.debug("New identity certifiers : {pubkey}".format(pubkey=current_identity.pubkey[:5]))
-                    self.graph_changed.emit()
-                    await self.add_certified_list(certified_list, current_identity, identity)
+                    certified_coro = asyncio.ensure_future(self.add_certified_list(certified_list,
+                                                                                   current_identity, identity))
+                    certifier_coro.add_done_callback(lambda f: self.graph_changed.emit())
+                    certified_coro.add_done_callback(lambda f: self.graph_changed.emit())
+                    await asyncio.gather(certifier_coro, certified_coro)
+
                     logging.debug("New identity certified : {pubkey}".format(pubkey=current_identity.pubkey[:5]))
-                    self.graph_changed.emit()
 
                     for cert in certified_list + certifier_list:
                         if cert['identity'] not in explorable[step + 1]:
diff --git a/src/sakia/core/graph/wot_graph.py b/src/sakia/core/graph/wot_graph.py
index b80a6979..c6723977 100644
--- a/src/sakia/core/graph/wot_graph.py
+++ b/src/sakia/core/graph/wot_graph.py
@@ -22,15 +22,21 @@ async def initialize(self, center_identity, account_identity):
         self.add_identity(center_identity, node_status)
 
         # create Identity from node metadata
-        certifier_list = await center_identity.unique_valid_certifiers_of(self.app.identities_registry,
-                                                                        self.community)
-        certified_list = await center_identity.unique_valid_certified_by(self.app.identities_registry,
-                                                                       self.community)
+        certifier_coro = asyncio.ensure_future(center_identity.unique_valid_certifiers_of(self.app.identities_registry,
+                                                                        self.community))
+        certified_coro = asyncio.ensure_future(center_identity.unique_valid_certified_by(self.app.identities_registry,
+                                                                       self.community))
+
+        certifier_list, certified_list = await asyncio.gather(certifier_coro, certified_coro)
 
         # populate graph with certifiers-of
-        await self.add_certifier_list(certifier_list, center_identity, account_identity)
+        certifier_coro = asyncio.ensure_future(self.add_certifier_list(certifier_list,
+                                                                       center_identity, account_identity))
         # populate graph with certified-by
-        await self.add_certified_list(certified_list, center_identity, account_identity)
+        certified_coro = asyncio.ensure_future(self.add_certified_list(certified_list,
+                                                                       center_identity, account_identity))
+
+        await asyncio.gather(certifier_coro, certified_coro)
 
     async def get_shortest_path_to_identity(self, account_identity, to_identity):
         """