diff --git a/lib/core/application.dart b/lib/core/application.dart
index 4ff4116..f936504 100644
--- a/lib/core/application.dart
+++ b/lib/core/application.dart
@@ -13,7 +13,7 @@ class Application {
       writeLog = (error, stack) => logError('$error:\n$stack');
       func();
     }, (error, stack) {
-      writeLog??(error, stack);
+      writeLog?.call(error, stack);
       errorListener(error, stack);
     });
   }
diff --git a/lib/platform/process.dart b/lib/platform/process.dart
index ee4bc05..4e841e2 100644
--- a/lib/platform/process.dart
+++ b/lib/platform/process.dart
@@ -161,13 +161,13 @@ class ProcessExecutor {
     if (Platform.isMacOS || Platform.isWindows) {
       workspace = workspace ?? Directory.systemTemp.path;
       if (printStdout_) {
-        logHandler ?? ('Execute Shell: $arg', LogType.verbose);
+        logHandler?.call('Execute Shell: $arg', LogType.verbose);
       }
       try {
         processData.process =
             await Process.start(exe, args, workingDirectory: workspace);
       } on Exception catch (e) {
-        logHandler ?? (e, LogType.error);
+        logHandler?.call(e.toString(), LogType.error);
       }
     } else {
       logHandler ?? ('This platform not support process executor.');
@@ -192,7 +192,7 @@ class ProcessExecutor {
         var file = File('$workspace/$tempFileName');
         processData.file = file;
         if (printStdout_) {
-          logHandler ??
+          logHandler?.call
               (
                 'Execute Shell: ${file.path} \n ${shell.toString()}',
                 LogType.verbose
@@ -208,14 +208,14 @@ class ProcessExecutor {
           processData.process = await Process.start(shellExe, [file.path],
               workingDirectory: workspace);
         } on Exception catch (e) {
-          logHandler ?? (e, LogType.error);
+          logHandler?.call(e.toString(), LogType.error);
         }
       } else if (Platform.isWindows) {
         workspace = workspace ?? Directory.systemTemp.path;
         var file = File('$workspace/$tempFileName');
         processData.file = file;
         if (printStdout_) {
-          logHandler ??
+          logHandler?.call
               (
                 'Execute Shell: ${file.path} \n ${shell.toString()}',
                 LogType.verbose
@@ -232,16 +232,16 @@ class ProcessExecutor {
           processData.process = await Process.start(
               'powershell', ['-NoProfile', '-File', file.absolute.path]);
         } on Exception catch (e) {
-          logHandler ?? (e, LogType.error);
+          logHandler?.call(e.toString(), LogType.error);
         }
       } else {
-        logHandler ??
+        logHandler?.call
             ('This platform not support process executor.', LogType.error);
       }
       c.complete(processData);
       await processData.waitForExit();
     } on Exception catch (e) {
-      logHandler ??
+      logHandler?.call
           ('General Exception in ProcessExecutor.start: $e', LogType.error);
     }
     return c.future;
@@ -257,12 +257,12 @@ class ProcessExecutor {
     workspace = workspace ?? Directory.systemTemp.path;
     var file = File('$workspace/$tempFileName');
     if (printStdout) {
-      logHandler ??
+      logHandler?.call
           (
             '---------------------------------------------------',
             LogType.verbose
           );
-      logHandler ??
+      logHandler?.call
           (
             'Shell Path: ${file.path} \nExecute Shell: ${shell.toString()}',
             LogType.verbose
@@ -277,7 +277,7 @@ class ProcessExecutor {
         processResult = await Process.run(shellExe, [file.path],
             workingDirectory: workspace);
       } on Exception catch (e) {
-        logHandler ?? (e, LogType.error);
+        logHandler?.call(e.toString(), LogType.error);
       } finally {
         file.deleteSync();
       }
@@ -298,7 +298,7 @@ class ProcessExecutor {
       file.deleteSync();
       c.complete(processResult);
     } else {
-      logHandler ??
+      logHandler?.call
           ('This platform not support process executor.', LogType.error);
       c.complete(null);
     }
@@ -308,7 +308,7 @@ class ProcessExecutor {
         if (decoder != null) {
           stdout = decoder.convert(stdout.codeUnits);
         }
-        logHandler ??
+        logHandler?.call
             (
               // ignore: prefer_interpolation_to_compose_strings
               '[ProcessExecutor] Result: $stdout',
@@ -320,7 +320,7 @@ class ProcessExecutor {
         if (decoder != null) {
           stderr = decoder.convert(stderr.codeUnits);
         }
-        logHandler ??
+        logHandler?.call
             (
               // ignore: prefer_interpolation_to_compose_strings
               '[ProcessExecutor] Exit Code: ${processResult.exitCode}\nError: $stderr',
diff --git a/lib/socket/socket_client.dart b/lib/socket/socket_client.dart
index b2b71b4..46fb253 100644
--- a/lib/socket/socket_client.dart
+++ b/lib/socket/socket_client.dart
@@ -28,11 +28,11 @@ class SocketClient {
       } catch (e) {
         print(e);
       }
-      resultListener??(connected);
+      resultListener?.call(connected);
       // ignore: argument_type_not_assignable_to_error_handler
     }).catchError((AsyncError e) {
       print('Unable to connect: $e');
-      resultListener??(connected);
+      resultListener?.call(connected);
     });
   }
 
@@ -52,7 +52,7 @@ class SocketClient {
   }
 
   void disconnect() {
-    eventDisconnected??();
+    eventDisconnected?.call();
     _socket!.close();
     _socket = null;
   }
@@ -111,6 +111,6 @@ class SocketClient {
 
   void _onDone() {
     print('Disconnected');
-    eventDisconnected??();
+    eventDisconnected?.call();
   }
 }