diff --git a/Cargo.lock b/Cargo.lock
index b0dd360..f190954 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -28,6 +28,7 @@ dependencies = [
  "log",
  "pyo3 0.20.0",
  "pyo3-log",
+ "rayon",
  "serde",
  "serde_json",
  "sha1",
@@ -144,6 +145,31 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "613f8cc01fe9cf1a3eb3d7f488fd2fa8388403e97039e2f73692932e291a770d"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
+dependencies = [
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "248e3bacc7dc6baa3b21e405ee045c3047101a49145e7e9eca583ab4c2ca5345"
+
 [[package]]
 name = "crypto-common"
 version = "0.1.6"
@@ -164,6 +190,12 @@ dependencies = [
  "crypto-common",
 ]
 
+[[package]]
+name = "either"
+version = "1.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "11157ac094ffbdde99aa67b23417ebdd801842852b500e395a45a9c0aac03e4a"
+
 [[package]]
 name = "flate2"
 version = "1.0.28"
@@ -485,6 +517,26 @@ dependencies = [
  "getrandom",
 ]
 
+[[package]]
+name = "rayon"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e4963ed1bc86e4f3ee217022bd855b297cef07fb9eac5dfa1f788b220b49b3bd"
+dependencies = [
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1465873a3dfdaa8ae7cb14b4383657caab0b3e8a0aa9ae8e04b044854c8dfce2"
+dependencies = [
+ "crossbeam-deque",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.2.16"
diff --git a/androscalpel/Cargo.toml b/androscalpel/Cargo.toml
index 6b39ffa..f176681 100644
--- a/androscalpel/Cargo.toml
+++ b/androscalpel/Cargo.toml
@@ -16,6 +16,7 @@ apk_frauder = { version = "0.1.0", path = "../apk_frauder" }
 log = "0.4.20"
 pyo3 = { version = "0.20.0", features = ["anyhow"] }
 pyo3-log = "0.8.3"
+rayon = "1.9.0"
 serde = { version = "1.0.195", features = ["derive"] }
 serde_json = "1.0.111"
 sha1 = "0.10.6"
diff --git a/androscalpel/src/apk.rs b/androscalpel/src/apk.rs
index 31d2331..823789c 100644
--- a/androscalpel/src/apk.rs
+++ b/androscalpel/src/apk.rs
@@ -15,6 +15,7 @@ use crate::Result;
 use crate::*;
 use androscalpel_serializer::Instruction as InsFormat;
 use androscalpel_serializer::*;
+use rayon::prelude::*;
 
 /// Represent an apk.
 #[pyclass]
@@ -33,10 +34,13 @@ impl Apk {
     /// Add the content of a dex file to the apk.
     pub fn add_dex_file(&mut self, data: &[u8]) -> Result<()> {
         let mut dex = DexFileReader::new(data)?;
-        for class in dex.get_class_defs() {
-            let class = self.get_class_from_dex_file(class, &dex)?;
-            self.classes.insert(class.descriptor.clone(), class);
-        }
+        let classes = dex
+            .get_class_defs()
+            .par_iter()
+            .map(|class| self.get_class_from_dex_file(class, &dex))
+            .map(|class| class.map(|class| (class.descriptor.clone(), class)))
+            .collect::<Result<Vec<_>, _>>()?;
+        self.classes.par_extend(classes);
         self.not_referenced_strings
             .extend(dex.get_not_resolved_strings()?.into_iter().map(DexString));
         Ok(())