diff --git a/forrustts-core/Cargo.toml b/forrustts-core/Cargo.toml
index 0301a838..f27c00a4 100644
--- a/forrustts-core/Cargo.toml
+++ b/forrustts-core/Cargo.toml
@@ -14,7 +14,7 @@ keywords = ["simulation", "tree_sequences", "tskit", "population_genetics"]
 [dependencies]
 thiserror = "1.0"
 # NOTE: automagically adds rand as a cargo feature
-rand = { version = "0.8.5", optional = true }
+rand = { version = "0.9.0", optional = true }
 
 [dev-dependencies]
 proptest = "1.1.0"
diff --git a/forrustts-core/src/rand_position.rs b/forrustts-core/src/rand_position.rs
index 33644ed3..f0b13925 100644
--- a/forrustts-core/src/rand_position.rs
+++ b/forrustts-core/src/rand_position.rs
@@ -1,4 +1,4 @@
-use rand::distributions::uniform::{SampleBorrow, SampleUniform, UniformInt, UniformSampler};
+use rand::distr::uniform::{SampleBorrow, SampleUniform, UniformInt, UniformSampler};
 use rand::prelude::Rng;
 
 use crate::Position;
@@ -9,25 +9,25 @@ pub struct UniformPos(UniformInt<i64>);
 
 impl UniformSampler for UniformPos {
     type X = Position;
-    fn new<B1, B2>(low: B1, high: B2) -> Self
+    fn new<B1, B2>(low: B1, high: B2) -> Result<Self, rand::distr::uniform::Error>
     where
         B1: SampleBorrow<Self::X> + Sized,
         B2: SampleBorrow<Self::X> + Sized,
     {
-        UniformPos(UniformInt::<i64>::new(
+        Ok(UniformPos(UniformInt::<i64>::new(
             i64::from(*low.borrow()),
             i64::from(*high.borrow()),
-        ))
+        )?))
     }
-    fn new_inclusive<B1, B2>(low: B1, high: B2) -> Self
+    fn new_inclusive<B1, B2>(low: B1, high: B2) -> Result<Self, rand::distr::uniform::Error>
     where
         B1: SampleBorrow<Self::X> + Sized,
         B2: SampleBorrow<Self::X> + Sized,
     {
-        UniformPos(UniformInt::<i64>::new_inclusive(
+        Ok(UniformPos(UniformInt::<i64>::new_inclusive(
             i64::from(*low.borrow()),
             i64::from(*high.borrow()),
-        ))
+        )?))
     }
     fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Self::X {
         Position::new_valid(self.0.sample(rng))
diff --git a/forrustts-core/tests/tests.rs b/forrustts-core/tests/tests.rs
index e017d0dc..3296f212 100644
--- a/forrustts-core/tests/tests.rs
+++ b/forrustts-core/tests/tests.rs
@@ -2,6 +2,7 @@
 mod test_rand_traits {
     use forrustts_core::Position;
     use proptest::prelude::*;
+    use rand::Rng;
     use rand::SeedableRng;
 
     proptest! {
@@ -11,7 +12,7 @@ mod test_rand_traits {
             if a != b { // else rand will panic
                 let lo = Position::new_valid(std::cmp::min(a, b));
                 let hi = Position::new_valid(std::cmp::max(a, b));
-                let upos = rand::distributions::Uniform::<Position>::new(lo, hi);
+                let upos = rand::distr::Uniform::<Position>::new(lo, hi).unwrap();
                 let mut rng = rand::rngs::StdRng::seed_from_u64(seed);
                 for _ in 0..100 {
                     let _ = rng.sample(upos);
@@ -27,7 +28,7 @@ mod test_rand_traits {
             if a != b { // else rand will panic
                 let lo = Position::new_valid(std::cmp::min(a, b));
                 let hi = Position::new_valid(std::cmp::max(a, b));
-                let upos = rand::distributions::Uniform::<Position>::new_inclusive(lo, hi);
+                let upos = rand::distr::Uniform::<Position>::new_inclusive(lo, hi).unwrap();
                 let mut rng = rand::rngs::StdRng::seed_from_u64(seed);
                 for _ in 0..100 {
                     let _ = rng.sample(upos);
diff --git a/forrustts-genetics/Cargo.toml b/forrustts-genetics/Cargo.toml
index eae9de75..3c658fe3 100644
--- a/forrustts-genetics/Cargo.toml
+++ b/forrustts-genetics/Cargo.toml
@@ -13,5 +13,5 @@ keywords = ["simulation", "tree_sequences", "tskit", "population_genetics"]
 
 [dependencies]
 forrustts-core = { version = "0.1.0", path = "../forrustts-core", features = ["rand"]}
-rand = "0.8.5"
-rand_distr = "0.4.3"
+rand = "0.9.0"
+rand_distr = "0.5.0"
diff --git a/forrustts-genetics/src/genetic_maps.rs b/forrustts-genetics/src/genetic_maps.rs
index f5aaf9ee..9103023b 100644
--- a/forrustts-genetics/src/genetic_maps.rs
+++ b/forrustts-genetics/src/genetic_maps.rs
@@ -238,7 +238,7 @@ impl GeneticMapBuilder {
 #[derive(Debug)]
 struct PoissonRegions {
     regions: Vec<rand_distr::Uniform<Position>>,
-    lookup: rand_distr::WeightedAliasIndex<f64>,
+    lookup: rand_distr::weighted::WeightedAliasIndex<f64>,
     poisson: rand_distr::Poisson<f64>,
 }
 
@@ -250,13 +250,13 @@ impl PoissonRegions {
         for p in poisson {
             let mean = p.mean();
             if mean > 0.0 {
-                let u = rand_distr::Uniform::new(p.left(), p.right());
+                let u = rand_distr::Uniform::new(p.left(), p.right()).ok()?;
                 regions.push(u);
                 weights.push(mean);
                 sum_poisson_means += mean;
             }
         }
-        let lookup = rand_distr::WeightedAliasIndex::new(weights).ok()?;
+        let lookup = rand_distr::weighted::WeightedAliasIndex::new(weights).ok()?;
         let poisson = rand_distr::Poisson::new(sum_poisson_means).ok()?;
         Some(Self {
             regions,
@@ -285,7 +285,7 @@ impl BernoulliRegions {
         for b in binomial {
             let prob = b.probability();
             if prob > 0.0 {
-                let u = rand_distr::Uniform::new(b.left(), b.right());
+                let u = rand_distr::Uniform::new(b.left(), b.right()).ok()?;
                 regions.push(u);
                 let dist = rand_distr::Bernoulli::new(prob).ok()?;
                 probabilities.push(dist);
@@ -357,7 +357,7 @@ impl GenerateBreakpoints for GeneticMap {
                 }
             }
         }
-        let uint = rand_distr::Uniform::new(0., 1.);
+        let uint = rand_distr::Uniform::new(0., 1.).unwrap();
         for i in self.independent_assortment.iter() {
             if rng.sample(uint) < 0.5 {
                 self.breakpoints.push(i.at());