diff -uNr atari800.orig/src/joycfg.c atari800/src/joycfg.c
--- atari800.orig/src/joycfg.c	2016-02-23 14:17:28.000000000 +0100
+++ atari800/src/joycfg.c	2016-02-23 14:24:09.282074155 +0100
@@ -434,7 +434,7 @@
   int i,no;
   int bad=0;
 
-  if ((fr=fopen("atari800.cfg","r"))==NULL)
+  if ((fr=fopen("atari800.cfg.libretro","r"))==NULL)
   {
     printf("Error opening configuration file.\n"
            "Execute this utility from atari800 dir after configuring it!\n");
@@ -494,9 +494,9 @@
   char string[256];
   int i;
 
-  if ((fr=fopen("atari800.cfg","r"))==NULL)
+  if ((fr=fopen("atari800.cfg.libretro","r"))==NULL)
   {
-    printf("Error opening atari800.cfg!\n");
+    printf("Error opening atari800.cfg.libretro!\n");
     return;
   }
   if ((fw=fopen("atari800.tmp","w"))==NULL)
@@ -521,10 +521,10 @@
   for (i=0;i<4;i++)
     fprintf(fw,"JOYSTICK_%i=%s\n",i,joyparams[joytypes[i]]);
   fclose(fw);
-  if (rename("atari800.tmp","atari800.cfg")==0)
+  if (rename("atari800.tmp","atari800.cfg.libretro")==0)
     printf("Configuration successfully saved.\n");
   else
-    printf("Error when renaming atari800.tmp to atari800.cfg!\n");
+    printf("Error when renaming atari800.tmp to atari800.cfg.libretro!\n");
 }
 /*------------------------------------------------------------------------*/
 int main()