diff --git a/configtool/build.py b/configtool/build.py
index 3768801..d9699fb 100644
--- a/configtool/build.py
+++ b/configtool/build.py
@@ -24,6 +24,9 @@ class ScriptTools:
     self.settings = settings
 
   def figureCommandPath(self, baseCommand):
+    if platform.startswith("win"):
+      baseCommand += ".exe"
+
     if self.settings.arduinodir:
       cmdpath = self.settings.arduinodir