diff --git a/concrete-optimizer/Cargo.toml b/concrete-optimizer/Cargo.toml
index 1df1b17cd..7fefbf731 100644
--- a/concrete-optimizer/Cargo.toml
+++ b/concrete-optimizer/Cargo.toml
@@ -14,7 +14,7 @@ file-lock = "2.1.6"
 static_init = "1.0.3"
 serde = { version = "1.0", features = ["derive"] }
 rmp-serde = "1.1.0"
-statrs = "0.16.0"
+puruspe = "0.2.0"
 
 [dev-dependencies]
 approx = "0.5"
diff --git a/concrete-optimizer/src/noise_estimator/error.rs b/concrete-optimizer/src/noise_estimator/error.rs
index 76a07f9cc..7f3848d64 100644
--- a/concrete-optimizer/src/noise_estimator/error.rs
+++ b/concrete-optimizer/src/noise_estimator/error.rs
@@ -4,11 +4,11 @@ use crate::utils::square;
 
 pub fn sigma_scale_of_error_probability(p_error: f64) -> f64 {
     // https://en.wikipedia.org/wiki/Error_function#Applications
-    statrs::function::erf::erfc_inv(p_error) * 2_f64.sqrt()
+    puruspe::inverfc(p_error) * 2_f64.sqrt()
 }
 
 pub fn error_probability_of_sigma_scale(sigma_scale: f64) -> f64 {
-    statrs::function::erf::erfc(sigma_scale / 2_f64.sqrt())
+    puruspe::erfc(sigma_scale / 2_f64.sqrt())
 }
 
 const LEFT_PADDING_BITS: u64 = 1;