diff --git a/master.py b/master.py
index eba8978..73dd744 100644
--- a/master.py
+++ b/master.py
@@ -29,6 +29,7 @@ regex_pkg_repo = re.compile(r"^(.*)-.*-.*-(?:x86_64|any)\.pkg\.tar\.zst(?:\.sig)
 fp = None
 update_last = time.time()
 copy_l = Lock()
+failed_l = Lock()
 repos = []
 
 
@@ -59,7 +60,7 @@ def build(pkgbuild: str, repo: str) -> None:
         logging.warning("[%s/%s/%s] Build failed. Check repo/logs for more information.", process_name, repo, name)
 
         # write packagename to failed list
-        with open(os.path.join(config["basedir"]["repo"], repo + "_failed.txt"), "a") as f:
+        with failed_l, open(os.path.join(config["basedir"]["repo"], repo + "_failed.txt"), "a") as f:
             f.write(name + "==" + str(parse_pkgbuild_ver(parsed=parsed)) + "\n")
 
         # write logs
@@ -194,6 +195,13 @@ def is_package_failed(package: str, ver: LegacyVersion, repo: str):
 
         if s[0] == package:
             if ver > LegacyVersion(s[1]):
+                with failed_l, open(os.path.join(config["basedir"]["repo"], repo + "_failed.txt")) as f:
+                    d = f.readlines()
+                    f.seek(0)
+                    f.truncate()
+                    for i in d:
+                        if i.strip("\n") != p:
+                            f.write(i)
                 return False
             else:
                 return True
@@ -202,8 +210,8 @@ def is_package_failed(package: str, ver: LegacyVersion, repo: str):
 
 def get_failed_packages(repo: str) -> list:
     if os.path.exists(os.path.join(config["basedir"]["repo"], repo + "_failed.txt")):
-        with open(os.path.join(config["basedir"]["repo"], repo + "_failed.txt")) as p:
-            return p.read().splitlines()
+        with failed_l, open(os.path.join(config["basedir"]["repo"], repo + "_failed.txt")) as p:
+            return p.readlines()
     else:
         return []
 
@@ -383,7 +391,7 @@ if __name__ == '__main__':
                     time.sleep(300)
                     do_repo_work()
             except KeyboardInterrupt:
-                with copy_l:
+                with copy_l, failed_l:
                     pool.close()
                     pool.terminate()
                     q.close()
diff --git a/utils.py b/utils.py
index 5298e1e..4a720aa 100644
--- a/utils.py
+++ b/utils.py
@@ -33,7 +33,7 @@ def increase_pkgrel(pkgbuild_file: str, parsed: dict = None) -> None:
     with open(pkgbuild_file, "r+", errors='ignore') as p:
         pkgbuild_str = p.read()
         p.truncate(0)
-        p.seek(0, 0)
+        p.seek(0)
 
         pkgbuild_str = regex_pkgrel.sub("pkgrel=" + parsed["pkgrel"] + ".1", pkgbuild_str)
         p.write(pkgbuild_str)