diff --git a/components/net/Cargo.toml b/components/net/Cargo.toml
index 9aa13502744..9d3e91631a6 100644
--- a/components/net/Cargo.toml
+++ b/components/net/Cargo.toml
@@ -44,6 +44,7 @@ rustc-serialize = "0.3"
 cookie = "0.1"
 regex = "0.1.14"
 regex_macros = "0.1.8"
+mime_guess = "1.1.1"
 flate2 = "0.2.0"
 uuid = "0.1.16"
 euclid = {version = "0.3", features = ["plugins"]}
diff --git a/components/net/file_loader.rs b/components/net/file_loader.rs
index a4348049d78..1519ec31b2d 100644
--- a/components/net/file_loader.rs
+++ b/components/net/file_loader.rs
@@ -3,6 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use mime_classifier::MIMEClassifier;
+use mime_guess::guess_mime_type;
 use net_traits::ProgressMsg::{Done, Payload};
 use net_traits::{LoadConsumer, LoadData, Metadata};
 use resource_task::{CancellationListener, ProgressSender};
@@ -70,7 +71,9 @@ pub fn factory(load_data: LoadData,
                         }
                         match read_block(reader) {
                             Ok(ReadStatus::Partial(buf)) => {
-                                let metadata = Metadata::default(url);
+                                let mut metadata = Metadata::default(url);
+                                let mime_type = guess_mime_type(file_path.as_path());
+                                metadata.set_content_type(Some(&mime_type));
                                 let progress_chan = start_sending_sniffed(senders, metadata,
                                                                           classifier, &buf);
                                 progress_chan.send(Payload(buf)).unwrap();
@@ -83,7 +86,9 @@ pub fn factory(load_data: LoadData,
                                 }
                             }
                             Ok(ReadStatus::EOF) => {
-                                let metadata = Metadata::default(url);
+                                let mut metadata = Metadata::default(url);
+                                let mime_type = guess_mime_type(file_path.as_path());
+                                metadata.set_content_type(Some(&mime_type));
                                 if let Ok(chan) = start_sending_sniffed_opt(senders,
                                                                             metadata,
                                                                             classifier,
diff --git a/components/net/lib.rs b/components/net/lib.rs
index 514be731f77..3fe4fba3d2c 100644
--- a/components/net/lib.rs
+++ b/components/net/lib.rs
@@ -20,6 +20,7 @@ extern crate flate2;
 extern crate brotli;
 extern crate hyper;
 extern crate ipc_channel;
+extern crate mime_guess;
 extern crate msg;
 extern crate net_traits;
 extern crate openssl;
diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index f0d37d70faa..2b16bd24fe6 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -1119,6 +1119,14 @@ dependencies = [
  "log 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "mime_guess"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "mime 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "miniz-sys"
 version = "0.1.6"
@@ -1182,6 +1190,7 @@ dependencies = [
  "hyper 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.1.0 (git+https://github.com/pcwalton/ipc-channel)",
  "log 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mime_guess 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
  "openssl 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/cef/Cargo.lock b/ports/cef/Cargo.lock
index 0fb84a80b8c..04a08181998 100644
--- a/ports/cef/Cargo.lock
+++ b/ports/cef/Cargo.lock
@@ -1071,6 +1071,14 @@ dependencies = [
  "log 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "mime_guess"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "mime 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "miniz-sys"
 version = "0.1.6"
@@ -1134,6 +1142,7 @@ dependencies = [
  "hyper 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.1.0 (git+https://github.com/pcwalton/ipc-channel)",
  "log 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mime_guess 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
  "openssl 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/gonk/Cargo.lock b/ports/gonk/Cargo.lock
index 531f2b92268..5074bc6ae33 100644
--- a/ports/gonk/Cargo.lock
+++ b/ports/gonk/Cargo.lock
@@ -1051,6 +1051,14 @@ dependencies = [
  "log 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "mime_guess"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "mime 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "miniz-sys"
 version = "0.1.6"
@@ -1114,6 +1122,7 @@ dependencies = [
  "hyper 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.1.0 (git+https://github.com/pcwalton/ipc-channel)",
  "log 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mime_guess 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
  "openssl 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",