diff --git a/lib/esptool/esptoolLinux/esptool b/lib/esptool/esptoolLinux/esptool
index 6f68f5d8..ed76da6a 100644
Binary files a/lib/esptool/esptoolLinux/esptool and b/lib/esptool/esptoolLinux/esptool differ
diff --git a/lib/esptool/esptoolMac/esptool b/lib/esptool/esptoolMac/esptool
index 96f45b20..d46bea83 100755
Binary files a/lib/esptool/esptoolMac/esptool and b/lib/esptool/esptoolMac/esptool differ
diff --git a/lib/esptool/esptoolWin/esptool.exe b/lib/esptool/esptoolWin/esptool.exe
index 31bb3539..242f2297 100644
Binary files a/lib/esptool/esptoolWin/esptool.exe and b/lib/esptool/esptoolWin/esptool.exe differ
diff --git a/nanoFirmwareFlasher.Library/EspTool.cs b/nanoFirmwareFlasher.Library/EspTool.cs
index a8ba74b6..7fb898c8 100644
--- a/nanoFirmwareFlasher.Library/EspTool.cs
+++ b/nanoFirmwareFlasher.Library/EspTool.cs
@@ -466,7 +466,6 @@ internal ExitCodes WriteFlash(
             var regexPattern = new StringBuilder();
             int counter = 1;
             var regexGroupNames = new List<string>();
-            string flashFreqParam;
 
             foreach (var part in partsToWrite)
             {
@@ -486,22 +485,9 @@ internal ExitCodes WriteFlash(
                 _ => "detect",
             };
 
-            // process flash frequency
-            if (_flashFrequency == -1)
-            {
-                // no flash frequency was requested on the CLI options
-                // defaulting to 'keep' to make this work with image files with checksum
-                flashFreqParam = "keep";
-            }
-            else
-            {
-                // compose option for flash freq para
-                flashFreqParam = $"{_flashFrequency}m";
-            }
-
             // execute write_flash command and parse the result; progress message can be found be searching for linefeed
             if (!RunEspTool(
-                $"write_flash --flash_mode {_flashMode} --flash_freq {flashFreqParam} --flash_size {flashSize} {partsArguments.ToString().Trim()}",
+                $"write_flash --flash_mode {_flashMode} --flash_freq {_flashFrequency}m --flash_size {flashSize} {partsArguments.ToString().Trim()}",
                 false,
                 useStandardBaudrate,
                 true,
@@ -637,7 +623,7 @@ private bool RunEspTool(
             if (!espTool.Start())
             {
                 throw new EspToolExecutionException("Error starting esptool!");
-            }
+            }           
 
             var messageBuilder = new StringBuilder();
 
diff --git a/nanoFirmwareFlasher.Tool/Options.cs b/nanoFirmwareFlasher.Tool/Options.cs
index b9f63623..2c4a9679 100644
--- a/nanoFirmwareFlasher.Tool/Options.cs
+++ b/nanoFirmwareFlasher.Tool/Options.cs
@@ -108,14 +108,14 @@ public class Options
         [Option(
             "flashmode",
             Required = false,
-            Default = "keep",
+            Default = "dio",
             HelpText = "Flash mode to use.")]
         public string Esp32FlashMode { get; set; }
 
         [Option(
             "flashfreq",
             Required = false,
-            Default = -1,
+            Default = 40,
             HelpText = "Flash frequency to use [MHz].")]
         public int Esp32FlashFrequency { get; set; }