diff --git a/components/finsh/shell.h b/components/finsh/shell.h
index 8741759ed47523870d2e8dcc5649cd931f8462ed..8f94e23e8b572ae33ce47ad093e873272271c979 100644
--- a/components/finsh/shell.h
+++ b/components/finsh/shell.h
@@ -78,7 +78,7 @@ struct finsh_shell
     struct finsh_parser parser;
 #endif
 
-    char line[FINSH_CMD_SIZE];
+    char line[FINSH_CMD_SIZE + 1];
     rt_uint16_t line_position;
     rt_uint16_t line_curpos;
 
@@ -107,4 +107,3 @@ const char *finsh_get_password(void);
 #endif
 
 #endif
-