diff --git a/src/main.cpp b/src/main.cpp
index 7ec1f81..08f7011 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -320,7 +320,7 @@ void sd_init() {
   }
  
   now = rtc.now();
-  char date_format[] = "DDhhmm";
+  char date_format[16] = "DDhhmm";
   char *date = now.toString(date_format);  
   strcat(fichier,date);
   char entete[] = "# YY-MM-DD:hh:mm:ss Vrot en tr/min \n";