diff --git a/.gitignore b/.gitignore
index 8c38c0e..197e37a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,5 @@
 **/*.rs.bk
 Cargo.lock
 /examples/filename*.png
+/.envrc
+/.direnv
diff --git a/Cargo.toml b/Cargo.toml
index da86b16..64bdfa4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "actix-form-data"
 description = "Multipart Form Data for Actix Web"
-version = "0.7.0-beta.0"
+version = "0.7.0-beta.1"
 license = "GPL-3.0"
 authors = ["asonix <asonix@asonix.dog>"]
 repository = "https://git.asonix.dog/asonix/actix-form-data.git"
@@ -10,7 +10,7 @@ keywords = ["actix", "form-data", "multipart", "async"]
 edition = "2021"
 
 [dependencies]
-actix-multipart = "0.4.0"
+actix-multipart = { version = "0.6.0", default-features = false }
 actix-rt = "2.5.0"
 actix-web = { version = "4.0.0", default-features = false }
 futures-util = "0.3.17"
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..1e4bcf3
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1685518550,
+        "narHash": "sha256-o2d0KcvaXzTrPRIo0kOLV0/QXHhDQ5DTi+OxcjO8xqY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "a1720a10a6cfe8234c0e93907ffe81be440f4cef",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1685564631,
+        "narHash": "sha256-8ywr3AkblY4++3lIVxmrWZFzac7+f32ZEhH/A8pNscI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4f53efe34b3a8877ac923b9350c874e3dcd5dc0a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..1426089
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,27 @@
+{
+  description = "A very basic flake";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+      in
+      {
+        packages.default = pkgs.hello;
+
+        devShell = with pkgs; mkShell {
+          nativeBuildInputs = [ cargo cargo-outdated cargo-zigbuild clippy gcc protobuf rust-analyzer rustc rustfmt ];
+
+          RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";
+        };
+
+        formatter = pkgs.nixpkgs-fmt;
+      });
+}
diff --git a/src/types.rs b/src/types.rs
index c5b11ab..e702296 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -32,7 +32,7 @@ use tracing::trace;
 #[derive(Debug)]
 pub struct FileMeta<T> {
     pub filename: String,
-    pub content_type: Mime,
+    pub content_type: Option<Mime>,
     pub result: T,
 }
 
@@ -155,7 +155,7 @@ impl<T> From<MultipartContent<T>> for Value<T> {
 pub type FileFn<T, E> = Box<
     dyn Fn(
             String,
-            Mime,
+            Option<Mime>,
             Pin<Box<dyn Stream<Item = Result<Bytes, Error>>>>,
         ) -> Pin<Box<dyn Future<Output = Result<T, E>>>>
 >;
@@ -215,7 +215,7 @@ impl<T, E> Field<T, E> {
     /// ```
     pub fn file<F, Fut>(f: F) -> Self
     where
-        F: Fn(String, Mime, Pin<Box<dyn Stream<Item = Result<Bytes, Error>>>>) -> Fut
+        F: Fn(String, Option<Mime>, Pin<Box<dyn Stream<Item = Result<Bytes, Error>>>>) -> Fut
             + Clone
             + 'static,
         Fut: Future<Output = Result<T, E>> + 'static,
@@ -437,8 +437,8 @@ impl<T, E> Map<T, E> {
             Some(NamePart::Map(name_part)) => self
                 .inner
                 .iter()
-                .find(|&&(ref item, _)| *item == *name_part)
-                .and_then(|&(_, ref field)| field.valid_field(name)),
+                .find(|(ref item, _)| *item == *name_part)
+                .and_then(|(_, ref field)| field.valid_field(name)),
             _ => None,
         }
     }
diff --git a/src/upload.rs b/src/upload.rs
index 8400701..8be60c0 100644
--- a/src/upload.rs
+++ b/src/upload.rs
@@ -117,7 +117,7 @@ where
 
     let file_size = Arc::new(AtomicUsize::new(0));
 
-    let content_type = field.content_type().clone();
+    let content_type = field.content_type().cloned();
 
     let max_file_size = form.max_file_size;