diff --git a/Cargo.toml b/Cargo.toml
index 418c2b9..73ab5ff 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,8 +22,8 @@ members = ["examples/*"]
 [dependencies]
 bytes = "1.4"
 indexmap = "2"
-rand = { version = "0.8.5", features = ["small_rng"] }
-rand_distr = "0.4.3"
+rand = { version = "0.9", features = ["small_rng"] }
+rand_distr = "0.5"
 regex = { version = "1", optional = true }
 scoped-tls = "1.0.1"
 tokio = { version = "1.25.0", features = ["full", "test-util"] }
diff --git a/src/builder.rs b/src/builder.rs
index b92a34a..60987e5 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -182,7 +182,7 @@ impl Builder {
     ///
     /// This will use default rng with entropy from the device running.
     pub fn build<'a>(&self) -> Sim<'a> {
-        self.build_with_rng(Box::new(rand::rngs::SmallRng::from_entropy()))
+        self.build_with_rng(Box::new(rand::rngs::SmallRng::from_os_rng()))
     }
 
     /// Build a sim with a provided `rng`.
diff --git a/src/sim.rs b/src/sim.rs
index 948ce62..289e92e 100644
--- a/src/sim.rs
+++ b/src/sim.rs
@@ -765,7 +765,7 @@ mod test {
             })
         };
 
-        let construct_a_first = sim.world.borrow_mut().rng.gen_bool(0.5);
+        let construct_a_first = sim.world.borrow_mut().rng.random_bool(0.5);
         if construct_a_first {
             make_a(&mut sim);
             make_b(&mut sim);
diff --git a/src/top.rs b/src/top.rs
index 40dbb02..ee362f5 100644
--- a/src/top.rs
+++ b/src/top.rs
@@ -507,13 +507,13 @@ impl Link {
     fn rand_partition(&self, global: &config::MessageLoss, rand: &mut dyn RngCore) -> bool {
         let config = self.config.message_loss.as_ref().unwrap_or(global);
         let fail_rate = config.fail_rate;
-        fail_rate > 0.0 && rand.gen_bool(fail_rate)
+        fail_rate > 0.0 && rand.random_bool(fail_rate)
     }
 
     fn rand_repair(&self, global: &config::MessageLoss, rand: &mut dyn RngCore) -> bool {
         let config = self.config.message_loss.as_ref().unwrap_or(global);
         let repair_rate = config.repair_rate;
-        repair_rate > 0.0 && rand.gen_bool(repair_rate)
+        repair_rate > 0.0 && rand.random_bool(repair_rate)
     }
 
     fn delay(&self, global: &config::Latency, rand: &mut dyn RngCore) -> Duration {