diff --git a/CHANGELOG.md b/CHANGELOG.md
index 814577805..c4f9ff6dd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Release History
 
+## Unreleased: mitmproxy next
+
+* fix some responses not being decoded properly if the encoding was uppercase #4735 (@Mattwmaster58)
+
 ## 4 August 2021: mitmproxy 7.0.2
 
 * Fix a WebSocket crash introduced in 7.0.1 (@mhils)
diff --git a/mitmproxy/net/encoding.py b/mitmproxy/net/encoding.py
index 9ed2163a4..854931e60 100644
--- a/mitmproxy/net/encoding.py
+++ b/mitmproxy/net/encoding.py
@@ -52,6 +52,7 @@ def decode(
     """
     if encoded is None:
         return None
+    encoding = encoding.lower()
 
     global _cache
     cached = (
@@ -67,7 +68,7 @@ def decode(
             decoded = custom_decode[encoding](encoded)
         except KeyError:
             decoded = codecs.decode(encoded, encoding, errors)  # type: ignore
-        if encoding in ("gzip", "deflate", "br", "zstd"):
+        if encoding in ("gzip", "deflate", "deflateraw", "br", "zstd"):
             _cache = CachedDecode(encoded, encoding, errors, decoded)
         return decoded
     except TypeError:
@@ -108,6 +109,7 @@ def encode(decoded: Union[None, str, bytes], encoding, errors='strict') -> Union
     """
     if decoded is None:
         return None
+    encoding = encoding.lower()
 
     global _cache
     cached = (
@@ -123,7 +125,7 @@ def encode(decoded: Union[None, str, bytes], encoding, errors='strict') -> Union
             encoded = custom_encode[encoding](decoded)
         except KeyError:
             encoded = codecs.encode(decoded, encoding, errors)  # type: ignore
-        if encoding in ("gzip", "deflate", "br", "zstd"):
+        if encoding in ("gzip", "deflate", "deflateraw", "br", "zstd"):
             _cache = CachedDecode(encoded, encoding, errors, decoded)
         return encoded
     except TypeError:
@@ -216,7 +218,7 @@ custom_decode = {
     "identity": identity,
     "gzip": decode_gzip,
     "deflate": decode_deflate,
-    "deflateRaw": decode_deflate,
+    "deflateraw": decode_deflate,
     "br": decode_brotli,
     "zstd": decode_zstd,
 }
@@ -225,7 +227,7 @@ custom_encode = {
     "identity": identity,
     "gzip": encode_gzip,
     "deflate": encode_deflate,
-    "deflateRaw": encode_deflate,
+    "deflateraw": encode_deflate,
     "br": encode_brotli,
     "zstd": encode_zstd,
 }
diff --git a/test/mitmproxy/net/test_encoding.py b/test/mitmproxy/net/test_encoding.py
index 55d7d6f38..328306e1d 100644
--- a/test/mitmproxy/net/test_encoding.py
+++ b/test/mitmproxy/net/test_encoding.py
@@ -17,6 +17,7 @@ def test_identity(encoder):
 
 @pytest.mark.parametrize("encoder", [
     'gzip',
+    'GZIP',
     'br',
     'deflate',
     'zstd',