diff --git a/build.c b/build.c
index 175c506c..ce9d01e7 100644
--- a/build.c
+++ b/build.c
@@ -52,6 +52,11 @@ SH_CommandResult RunCommand(Arena *arena, String command)
     return res;
 }
 
+void KillRunningProcesses(void)
+{
+    SH_RunCommand(Lit("taskkill /im PowerPlay.exe /f /fi \"STATUS eq RUNNING\""), true);
+}
+
 /* ========================== *
  * Step
  * ========================== */
@@ -977,6 +982,7 @@ void OnBuild(StringList cli_args)
     Bool success = true;
     I64 step_count = sl->count;
     if (step_count > 0) {
+        KillRunningProcesses();
         ExecuteSteps();
 
         Step *s = sl->first;