diff --git a/Cargo.lock b/Cargo.lock
index ee1479e..e2f1c5c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6,6 +6,7 @@ version = 3
 name = "androscalpel"
 version = "0.1.0"
 dependencies = [
+ "androscalpel_serializer",
  "pyo3",
 ]
 
diff --git a/androscalpel/Cargo.toml b/androscalpel/Cargo.toml
index 0136047..655050f 100644
--- a/androscalpel/Cargo.toml
+++ b/androscalpel/Cargo.toml
@@ -9,4 +9,5 @@ name = "androscalpel"
 crate-type = ["cdylib"]
 
 [dependencies]
+androscalpel_serializer = { version = "0.1.0", path = "../androscalpel_serializer" }
 pyo3 = "0.19.0"
diff --git a/androscalpel/src/apk.rs b/androscalpel/src/apk.rs
index a5b4562..188a598 100644
--- a/androscalpel/src/apk.rs
+++ b/androscalpel/src/apk.rs
@@ -1,9 +1,9 @@
 //! Representation of an apk.
-
-use crate::Class;
-
 use pyo3::prelude::*;
 
+use crate::{Class, Result};
+use androscalpel_serializer::DexFileReader;
+
 /// Represent an apk.
 #[pyclass]
 #[derive(Debug, Clone)]
@@ -14,8 +14,9 @@ pub struct Apk {
 
 impl Apk {
     /// Add the content of a dex file to the apk.
-    pub fn add_dex_file(&mut self) {
-        todo!()
+    pub fn add_dex_file(&mut self, data: &[u8]) -> Result<()> {
+        let dex = DexFileReader::new(data)?;
+        Ok(())
     }
 }
 
diff --git a/androscalpel/src/lib.rs b/androscalpel/src/lib.rs
index 7ba3268..644c3f4 100644
--- a/androscalpel/src/lib.rs
+++ b/androscalpel/src/lib.rs
@@ -1,3 +1,4 @@
+use pyo3::exceptions::PyValueError;
 use pyo3::prelude::*;
 
 pub mod apk;
@@ -6,6 +7,62 @@ pub mod class;
 pub use apk::*;
 pub use class::*;
 
+#[derive(Debug)]
+pub enum Error {
+    InputTooSmall(String),
+    SerializationError(String),
+    DeserializationError(String),
+    InvalidStringEncoding(String),
+    InconsistantStruct(String),
+}
+
+impl From<androscalpel_serializer::Error> for Error {
+    fn from(error: androscalpel_serializer::Error) -> Self {
+        match error {
+            androscalpel_serializer::Error::InputTooSmall(err) => Self::InputTooSmall(err),
+            androscalpel_serializer::Error::SerializationError(err) => {
+                Self::SerializationError(err)
+            }
+            androscalpel_serializer::Error::DeserializationError(err) => {
+                Self::DeserializationError(err)
+            }
+            androscalpel_serializer::Error::InvalidStringEncoding(err) => {
+                Self::InvalidStringEncoding(err)
+            }
+            androscalpel_serializer::Error::InconsistantStruct(err) => {
+                Self::InconsistantStruct(err)
+            }
+        }
+    }
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            Self::InputTooSmall(msg) => write!(f, "InputTooSmall: {}", msg),
+            Self::SerializationError(msg) => write!(f, "SerializationError: {}", msg),
+            Self::DeserializationError(msg) => write!(f, "DeserializationError: {}", msg),
+            Self::InvalidStringEncoding(msg) => write!(f, "InvalidStringEncoding: {}", msg),
+            Self::InconsistantStruct(msg) => write!(f, "InconsistantStruct: {}", msg),
+        }
+    }
+}
+impl std::error::Error for Error {}
+
+impl From<Error> for PyErr {
+    fn from(error: Error) -> Self {
+        match error {
+            Error::InputTooSmall(err) => PyValueError::new_err(format!("{err}")),
+            Error::SerializationError(err) => PyValueError::new_err(format!("{err}")),
+            Error::DeserializationError(err) => PyValueError::new_err(format!("{err}")),
+            Error::InvalidStringEncoding(err) => PyValueError::new_err(format!("{err}")),
+            Error::InconsistantStruct(err) => PyValueError::new_err(format!("{err}")),
+        }
+    }
+}
+
+pub type Result<T> = core::result::Result<T, Error>;
+
 /// Androscalpel.
 #[pymodule]
 fn androscalpel(_py: Python, m: &PyModule) -> PyResult<()> {
diff --git a/androscalpel_serializer/src/core/mod.rs b/androscalpel_serializer/src/core/mod.rs
index dc4c9db..5ccb3bf 100644
--- a/androscalpel_serializer/src/core/mod.rs
+++ b/androscalpel_serializer/src/core/mod.rs
@@ -27,11 +27,11 @@ impl<T: Read + Seek> ReadSeek for T {}
 impl std::fmt::Display for Error {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
-            Self::InputTooSmall(msg) => write!(f, "Error: {}", msg),
-            Self::SerializationError(msg) => write!(f, "Error: {}", msg),
-            Self::DeserializationError(msg) => write!(f, "Error: {}", msg),
-            Self::InvalidStringEncoding(msg) => write!(f, "Error: {}", msg),
-            Self::InconsistantStruct(msg) => write!(f, "Error: {}", msg),
+            Self::InputTooSmall(msg) => write!(f, "{}", msg),
+            Self::SerializationError(msg) => write!(f, "{}", msg),
+            Self::DeserializationError(msg) => write!(f, "{}", msg),
+            Self::InvalidStringEncoding(msg) => write!(f, "{}", msg),
+            Self::InconsistantStruct(msg) => write!(f, "{}", msg),
         }
     }
 }