diff --git a/components/log/host_test/log_test/main/log_test.cpp b/components/log/host_test/log_test/main/log_test.cpp
index 4582ffb21b..8db973ca79 100644
--- a/components/log/host_test/log_test/main/log_test.cpp
+++ b/components/log/host_test/log_test/main/log_test.cpp
@@ -95,7 +95,7 @@ private:
     int print_to_buffer(const char *format, va_list args)
     {
         // Added support for multi-line log, for example ESP_LOG_BUFFER...
-        int ret = vsnprintf(&print_buffer[buffer_idx], BUFFER_SIZE, format, args);
+        int ret = vsnprintf(&print_buffer[buffer_idx], BUFFER_SIZE - buffer_idx, format, args);
         buffer_idx += ret;
         return ret;
     }