diff --git a/Dockerfile b/Dockerfile
index c26c6ae..9a1477b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 ARG PYTHON_VERSION=alpine
 
-FROM python:$PYTHON_VERSION as base
+FROM python:$PYTHON_VERSION AS base
 
 ENV APP_ROOT=/app
 WORKDIR $APP_ROOT
@@ -12,7 +12,7 @@ COPY requirements.txt .
 RUN python -m pip install --upgrade pip && \
     python -m pip install -r requirements.txt
 
-FROM base as compile
+FROM base AS compile
 
 ENV USER_ID=65535
 ENV GROUP_ID=65535
diff --git a/pyredis-dump.py b/pyredis-dump.py
index 749f1b4..e52afbf 100755
--- a/pyredis-dump.py
+++ b/pyredis-dump.py
@@ -18,6 +18,8 @@ def __init__(self, *a, **kw):
 
     def get_one(self, key):
         type = self.type(key)
+        if type == b'none':  # Handle non-existing keys gracefully
+            return None  # Or any other appropriate handling
         p = self.pipeline()
         p.watch(key)
         p.multi()
@@ -51,7 +53,9 @@ def get_one(self, key):
 
     def pattern_iter(self, pattern="*"):
         for key in self.keys(pattern):
-            yield self.get_one(key)
+            result = self.get_one(key)
+            if result is not None:
+                yield result
 
     def dump(self, outfile=None, pattern="*"):
         for type, key, ttl, expire_at, value in self.pattern_iter(pattern):
diff --git a/requirements.txt b/requirements.txt
index 968b7c7..f2ea803 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,2 @@
-ConfigArgParse==1.5.3
-redis==4.3.3
+ConfigArgParse==1.7
+redis==5.0.7