diff --git a/plugins/out_s3/s3.c b/plugins/out_s3/s3.c
index 1718cc735d4..57e68e6ef90 100644
--- a/plugins/out_s3/s3.c
+++ b/plugins/out_s3/s3.c
@@ -317,6 +317,7 @@ static int write_seq_index(char *seq_index_file, uint64_t seq_index)
 
     ret = fprintf(fp, "%"PRIu64, seq_index);
     if (ret < 0) {
+        fclose(fp);
         flb_errno();
         return -1;
     }