diff --git a/legendary/api/egs.py b/legendary/api/egs.py
index c904d4b..f0604cd 100644
--- a/legendary/api/egs.py
+++ b/legendary/api/egs.py
@@ -33,8 +33,19 @@ class EPCAPI:
         self.user = None
 
     def resume_session(self, session):
+        self.session.headers['Authorization'] = f'bearer {session["access_token"]}'
+        r = self.session.get(f'https://{self._oauth_host}/account/api/oauth/verify')
+        if r.status_code >= 500:
+            r.raise_for_status()
+
+        j = r.json()
+        if 'errorMessage' in j:
+            self.log.warning(f'Login to EGS API failed with errorCode: {j["errorCode"]}')
+            raise InvalidCredentialsError(j['errorCode'])
+
+        # update other data
+        session.update(j)
         self.user = session
-        self.session.headers['Authorization'] = f'bearer {self.user["access_token"]}'
         return self.user
 
     def start_session(self, refresh_token: str = None, exchange_token: str = None) -> dict:
diff --git a/legendary/core.py b/legendary/core.py
index f4bb3d1..e5b2148 100644
--- a/legendary/core.py
+++ b/legendary/core.py
@@ -93,15 +93,22 @@ class LegendaryCore:
             raise ValueError('No saved credentials')
 
         if self.lgd.userdata['expires_at']:
-            dt_old = datetime.fromisoformat(self.lgd.userdata['expires_at'][:-1])
+            dt_exp = datetime.fromisoformat(self.lgd.userdata['expires_at'][:-1])
             dt_now = datetime.utcnow()
-            td = dt_now - dt_old
+            td = dt_now - dt_exp
 
             # if session still has at least 10 minutes left we can re-use it.
-            if dt_old > dt_now and td.total_seconds() < (self.lgd.userdata['expires_in'] - 600):
-                self.log.debug('Reusing existing login session...')
-                self.egs.resume_session(self.lgd.userdata)
-                return True
+            if dt_exp > dt_now and abs(td.total_seconds()) > 600:
+                self.log.debug('Trying to re-use existing login session...')
+                try:
+                    self.egs.resume_session(self.lgd.userdata)
+                    return True
+                except InvalidCredentialsError as e:
+                    self.log.warning(f'Resuming failed due to invalid credentials: {e!r}')
+                except Exception as e:
+                    self.log.warning(f'Resuming failed for unknown reason: {e!r}')
+                # If verify fails just continue the normal authentication process
+                self.log.info('Falling back to using refresh token...')
 
         try:
             userdata = self.egs.start_session(self.lgd.userdata['refresh_token'])