diff --git a/Cargo.toml b/Cargo.toml
index 553e294..547a8b8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,7 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-ndarray = {version="*", features=["approx"]}
+ndarray = {version="*", features=["approx-0_5"]}
 thiserror = "*"
 rand = "*"
 bimap = "*"
@@ -15,4 +15,4 @@ statrs = "*"
 rand_chacha = "*"
 
 [dev-dependencies]
-approx = "*"
+approx = { package = "approx", version = "0.5" }
diff --git a/tests/parameter_learning.rs b/tests/parameter_learning.rs
index 5de02d7..70f998c 100644
--- a/tests/parameter_learning.rs
+++ b/tests/parameter_learning.rs
@@ -10,6 +10,7 @@ use reCTBN::tools::*;
 use utils::*;
 
 extern crate approx;
+use crate::approx::AbsDiffEq;
 
 fn learn_binary_cim<T: ParameterLearning>(pl: T) {
     let mut net = CtbnNetwork::new();