diff --git a/src/u_tools.pas b/src/u_tools.pas
index d0da48b3..ac43f26e 100644
--- a/src/u_tools.pas
+++ b/src/u_tools.pas
@@ -18,6 +18,7 @@ type
   TToolItem = class(TCollectionItem)
   private
     fToolItems: TToolItems;
+    fTerminatedFlag: boolean;
     fNextToolAlias: string;
     fProcess: TDexedProcess;
     fExecutable: TFilename;
@@ -190,6 +191,7 @@ const
   confSpec = 'Are you sure you want to execute the "%s" tool ?';
 begin
   u_processes.killProcess(fProcess);
+  fTerminatedFlag := false;
 
   if fMsgs = nil then
     fMsgs := getMessageDisplay;
@@ -263,6 +265,9 @@ begin
   end;
   if (not fProcess.Running) then
   begin
+    if fTerminatedFlag then
+      exit;
+    fTerminatedFlag := true;
     if fProcess.ExitStatus <> 0 then
     begin
       fMsgs.message(format('error: the tool (%s) has returned the status %s',