diff --git a/src/Observable/CallObservable.php b/src/Observable/CallObservable.php
index 6f99871..c2e8e98 100644
--- a/src/Observable/CallObservable.php
+++ b/src/Observable/CallObservable.php
@@ -67,7 +67,7 @@ public function _subscribe(ObserverInterface $observer): DisposableInterface
                         new ResultMessage($msg->getRequestId(), (object)['progress' => false])
                     ], $this->scheduler);
                 }
-                return Observable::just($msg);
+                return Observable::of($msg);
             })
             ->share();
 
diff --git a/src/Observable/RegisterObservable.php b/src/Observable/RegisterObservable.php
index acd1be8..fb49d2a 100644
--- a/src/Observable/RegisterObservable.php
+++ b/src/Observable/RegisterObservable.php
@@ -106,12 +106,12 @@ function () use (&$completed, $observer, $unregister) {
                     } else {
                         $result = call_user_func_array($this->callback, $msg->getArguments());
                     }
-                } catch (\Exception $e) {
+                } catch (\Throwable $e) {
                     $this->invocationErrors->onNext(new WampInvocationException($msg));
-                    return Observable::emptyObservable($this->scheduler);
+                    return Observable::empty($this->scheduler);
                 }
 
-                $resultObs = $result instanceof Observable ? $result : Observable::just($result, $this->scheduler);
+                $resultObs = $result instanceof Observable ? $result : Observable::of($result, $this->scheduler);
 
                 if (($this->options['progress'] ?? false) === false) {
                     $returnObs = $resultObs
@@ -125,7 +125,7 @@ function () use (&$completed, $observer, $unregister) {
                         ->map(function ($value) use ($msg) {
                             return [$value, $msg, $this->options];
                         })
-                        ->concat(Observable::just([null, $msg, ["progress" => false]], $this->scheduler));
+                        ->concat(Observable::of([null, $msg, ["progress" => false]], $this->scheduler));
                 }
 
                 $interruptMsg = $this->messages
@@ -136,9 +136,9 @@ function () use (&$completed, $observer, $unregister) {
 
                 return $returnObs
                     ->takeUntil($interruptMsg)
-                    ->catchError(function (\Exception $ex) use ($msg) {
+                    ->catch(function (\Throwable $ex) use ($msg) {
                         $this->invocationErrors->onNext(new WampInvocationException($msg));
-                        return Observable::emptyObservable($this->scheduler);
+                        return Observable::empty($this->scheduler);
                     });
 
             })