diff --git a/test/test_read_file.c b/test/test_read_file.c
index 5bef1f4..dcd8d68 100644
--- a/test/test_read_file.c
+++ b/test/test_read_file.c
@@ -13,6 +13,7 @@ START_TEST (test_read_file_non_existing_file)
     size_t len;
     int saved_errno;
 
+    errno = 0;
     content = uc_read_file("non existing file 123765", &len, 1000000000);
     saved_errno = errno;