diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6492045..89557bb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.3.4 (2017-05-10)
+- sync dlcs (fixes #12)
+- break content deserializing and sync code into smaller pieces (fixes #9)
+
 ## 0.3.3 (2017-05-09)
 - normalize content directory names (fixes #11)
 
diff --git a/Cargo.lock b/Cargo.lock
index a6fb3ef..78c132b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,6 @@
 [root]
 name = "gog-sync"
-version = "0.3.3"
+version = "0.3.4"
 dependencies = [
  "chrono 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.24.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/Cargo.toml b/Cargo.toml
index ea3391c..4478e65 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "gog-sync"
-version = "0.3.3"
+version = "0.3.4"
 authors = ["Sebastian Hugentobler <sebastian@vanwa.ch>"]
 description = "Synchronizes a GOG library with a local folder."
 documentation = "https://docs.rs/crate/gog-sync"
diff --git a/src/gog.rs b/src/gog.rs
index 6361dae..8137c55 100644
--- a/src/gog.rs
+++ b/src/gog.rs
@@ -252,6 +252,14 @@ impl<'a> Gog<'a> {
         fs::create_dir_all(&data_root)?;
         let data_uri = format!("https://embed.gog.com{}", relative_uri);
 
+        let filename = self.api_request_get_filename(&data_uri)?;
+        let file_path = Path::new(&data_root).join(&filename);
+
+        if file_path.exists() {
+            info!("{} for {} already exists", &filename, content_title);
+            return Ok(filename.to_owned());
+        }
+
         info!("downloading {} for {}...", &relative_uri, content_title);
         self.api_request_download(data_uri.as_str(), &data_root)
     }
@@ -422,8 +430,7 @@ impl<'a> Gog<'a> {
             content_ids.push(content_id_parsed);
         }
 
-        //Ok(content_ids)
-        Ok(vec![1207658995])
+        Ok(content_ids)
     }
 
     fn api_request_ensure_token(&mut self, response: &str) -> Result<bool, GogError> {
@@ -452,6 +459,15 @@ impl<'a> Gog<'a> {
         }
     }
 
+    fn api_request_get_filename(&mut self, uri: &str) -> Result<String, GogError> {
+        let response = self.http_client.get_filename(uri)?;
+        if self.api_request_ensure_token(&response)? {
+            Ok(self.http_client.get_filename(uri)?)
+        } else {
+            Ok(response)
+        }
+    }
+
     fn api_request_download(&mut self, uri: &str, path: &PathBuf) -> Result<String, GogError> {
         let response = self.http_client.download(uri, path)?;
         if self.api_request_ensure_token(&response)? {
diff --git a/src/http.rs b/src/http.rs
index 61335ff..c6b6f29 100644
--- a/src/http.rs
+++ b/src/http.rs
@@ -96,10 +96,11 @@ impl Http {
         self.curl.url(uri)?;
         {
             let mut transfer = self.curl.transfer();
-            transfer.write_function(|new_data| {
-                    data.extend_from_slice(new_data);
-                    Ok(new_data.len())
-                })?;
+            transfer
+                .write_function(|new_data| {
+                                    data.extend_from_slice(new_data);
+                                    Ok(new_data.len())
+                                })?;
 
             transfer.perform()?;
         }
@@ -129,6 +130,46 @@ impl Http {
         }
     }
 
+    /// Find the filename for a download uri.
+    ///
+    /// Useful if the initial link gets redirected.
+    ///
+    /// The filename is taken from the last URI segment and returned in the result.
+    /// # Example
+    /// ```
+    /// use http::Http;
+    /// use std::path::Path;
+    ///
+    /// let mut http_client = Http::new();
+    ///
+    /// http_client.get_filename("https://example.com/sed");
+    /// ```
+    pub fn get_filename(&mut self, download_uri: &str) -> Result<String, HttpError> {
+        self.curl.url(download_uri)?;
+        self.curl.nobody(true)?;
+        self.curl.perform()?;
+        self.curl.nobody(false)?;
+
+        let download_url_string = match self.curl.effective_url()? {
+            Some(value) => value,
+            None => return Err(HttpError::Error("Can't get effective download url.")),
+        };
+
+        let download_url = Url::parse(download_url_string)?;
+
+        let download_url_segments = match download_url.path_segments() {
+            Some(value) => value,
+            None => return Err(HttpError::Error("Can't parse download segments.")),
+        };
+
+        let file_name = match download_url_segments.last() {
+            Some(value) => value,
+            None => return Err(HttpError::Error("No segments in download url.")),
+        };
+
+        Ok(file_name.to_owned())
+    }
+
     /// Download a file to the specified folder without creating the folder.
     ///
     /// The filename is taken from the last URI segment and returned in the result.
@@ -152,13 +193,14 @@ impl Http {
         self.curl.url(download_uri)?;
         {
             let mut transfer = self.curl.transfer();
-            transfer.write_function(|data| {
-                    match file_download.write(data) {
-                        Ok(_) => Ok(()),
-                        Err(error) => Err(HttpError::IOError(error)),
-                    }?;
-                    Ok(data.len())
-                })?;
+            transfer
+                .write_function(|data| {
+                                    match file_download.write(data) {
+                                        Ok(_) => Ok(()),
+                                        Err(error) => Err(HttpError::IOError(error)),
+                                    }?;
+                                    Ok(data.len())
+                                })?;
             transfer.perform()?;
         }
 
diff --git a/src/main.rs b/src/main.rs
index 0c0bcd9..10d7b7d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -29,7 +29,7 @@ fn main() {
     env_logger::init().unwrap();
 
     let matches = App::new("Gog Synchronizer")
-        .version("0.3.3")
+        .version("0.3.4")
         .author("Sebastian Hugentobler <sebastian@vanwa.ch>")
         .about("Synchronizes your gog library to a local folder.")
         .arg(Arg::with_name("game-storage")