diff --git a/Cargo.toml b/Cargo.toml
index 15b06e4e..b295a5fe 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,3 +44,8 @@ anyhow = "1.0"
 version = "0.32"
 default-features = false
 features = ["macros"]
+
+[lints.rust.unexpected_cfgs]
+level = "warn"
+# Set by cargo-llvm-cov when running on nightly
+check-cfg = ['cfg(coverage_nightly)']
diff --git a/src/distribution/beta.rs b/src/distribution/beta.rs
index 763945d6..e20ea302 100644
--- a/src/distribution/beta.rs
+++ b/src/distribution/beta.rs
@@ -38,6 +38,7 @@ pub enum BetaError {
 }
 
 impl std::fmt::Display for BetaError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             BetaError::ShapeAInvalid => write!(f, "Shape A is NaN, zero or negative"),
diff --git a/src/distribution/binomial.rs b/src/distribution/binomial.rs
index 9f5ffc47..1d86283d 100644
--- a/src/distribution/binomial.rs
+++ b/src/distribution/binomial.rs
@@ -34,6 +34,7 @@ pub enum BinomialError {
 }
 
 impl std::fmt::Display for BinomialError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             BinomialError::ProbabilityInvalid => write!(f, "Probability is NaN or not in [0, 1]"),
diff --git a/src/distribution/categorical.rs b/src/distribution/categorical.rs
index 9cd95a9d..cb3c7ea8 100644
--- a/src/distribution/categorical.rs
+++ b/src/distribution/categorical.rs
@@ -41,6 +41,7 @@ pub enum CategoricalError {
 }
 
 impl std::fmt::Display for CategoricalError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             CategoricalError::ProbMassEmpty => write!(f, "Probability mass is empty"),
diff --git a/src/distribution/cauchy.rs b/src/distribution/cauchy.rs
index a8815349..5ba7f69f 100644
--- a/src/distribution/cauchy.rs
+++ b/src/distribution/cauchy.rs
@@ -34,6 +34,7 @@ pub enum CauchyError {
 }
 
 impl std::fmt::Display for CauchyError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             CauchyError::LocationInvalid => write!(f, "Location is NaN"),
diff --git a/src/distribution/chi.rs b/src/distribution/chi.rs
index cce8535f..796fcd23 100644
--- a/src/distribution/chi.rs
+++ b/src/distribution/chi.rs
@@ -32,6 +32,7 @@ pub enum ChiError {
 }
 
 impl std::fmt::Display for ChiError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             ChiError::FreedomInvalid => {
diff --git a/src/distribution/dirac.rs b/src/distribution/dirac.rs
index 142f8c12..18e70f9b 100644
--- a/src/distribution/dirac.rs
+++ b/src/distribution/dirac.rs
@@ -26,6 +26,7 @@ pub enum DiracError {
 }
 
 impl std::fmt::Display for DiracError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             DiracError::ValueInvalid => write!(f, "Value v is NaN"),
diff --git a/src/distribution/dirichlet.rs b/src/distribution/dirichlet.rs
index b8aaad86..2670929a 100644
--- a/src/distribution/dirichlet.rs
+++ b/src/distribution/dirichlet.rs
@@ -43,6 +43,7 @@ pub enum DirichletError {
 }
 
 impl std::fmt::Display for DirichletError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             DirichletError::AlphaTooShort => write!(f, "Alpha contains less than two elements"),
diff --git a/src/distribution/discrete_uniform.rs b/src/distribution/discrete_uniform.rs
index be851b62..524bc2a3 100644
--- a/src/distribution/discrete_uniform.rs
+++ b/src/distribution/discrete_uniform.rs
@@ -31,6 +31,7 @@ pub enum DiscreteUniformError {
 }
 
 impl std::fmt::Display for DiscreteUniformError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             DiscreteUniformError::MinMaxInvalid => write!(f, "Maximum is less than minimum"),
diff --git a/src/distribution/exponential.rs b/src/distribution/exponential.rs
index 1389b1e4..ec30d1f7 100644
--- a/src/distribution/exponential.rs
+++ b/src/distribution/exponential.rs
@@ -33,6 +33,7 @@ pub enum ExpError {
 }
 
 impl std::fmt::Display for ExpError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             ExpError::RateInvalid => write!(f, "Rate is NaN, zero or less than zero"),
diff --git a/src/distribution/fisher_snedecor.rs b/src/distribution/fisher_snedecor.rs
index a50ed42a..610da130 100644
--- a/src/distribution/fisher_snedecor.rs
+++ b/src/distribution/fisher_snedecor.rs
@@ -37,6 +37,7 @@ pub enum FisherSnedecorError {
 }
 
 impl std::fmt::Display for FisherSnedecorError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             FisherSnedecorError::Freedom1Invalid => {
diff --git a/src/distribution/gamma.rs b/src/distribution/gamma.rs
index 201d0cfd..b6055c77 100644
--- a/src/distribution/gamma.rs
+++ b/src/distribution/gamma.rs
@@ -39,6 +39,7 @@ pub enum GammaError {
 }
 
 impl std::fmt::Display for GammaError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             GammaError::ShapeInvalid => write!(f, "Shape is NaN zero, or less than zero."),
diff --git a/src/distribution/geometric.rs b/src/distribution/geometric.rs
index dfb28ef6..41e35f52 100644
--- a/src/distribution/geometric.rs
+++ b/src/distribution/geometric.rs
@@ -33,6 +33,7 @@ pub enum GeometricError {
 }
 
 impl std::fmt::Display for GeometricError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             GeometricError::ProbabilityInvalid => write!(f, "Probability is NaN or not in (0, 1]"),
diff --git a/src/distribution/hypergeometric.rs b/src/distribution/hypergeometric.rs
index c3ba5a3a..7da6f45a 100644
--- a/src/distribution/hypergeometric.rs
+++ b/src/distribution/hypergeometric.rs
@@ -28,6 +28,7 @@ pub enum HypergeometricError {
 }
 
 impl std::fmt::Display for HypergeometricError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             HypergeometricError::TooManySuccesses => write!(f, "successes > population"),
diff --git a/src/distribution/inverse_gamma.rs b/src/distribution/inverse_gamma.rs
index 1f1bee4b..a36c7e17 100644
--- a/src/distribution/inverse_gamma.rs
+++ b/src/distribution/inverse_gamma.rs
@@ -37,6 +37,7 @@ pub enum InverseGammaError {
 }
 
 impl std::fmt::Display for InverseGammaError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             InverseGammaError::ShapeInvalid => {
diff --git a/src/distribution/laplace.rs b/src/distribution/laplace.rs
index d4f6fc16..13f03a55 100644
--- a/src/distribution/laplace.rs
+++ b/src/distribution/laplace.rs
@@ -34,6 +34,7 @@ pub enum LaplaceError {
 }
 
 impl std::fmt::Display for LaplaceError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             LaplaceError::LocationInvalid => write!(f, "Location is NaN"),
diff --git a/src/distribution/log_normal.rs b/src/distribution/log_normal.rs
index 9075bfd2..49380d2b 100644
--- a/src/distribution/log_normal.rs
+++ b/src/distribution/log_normal.rs
@@ -38,6 +38,7 @@ pub enum LogNormalError {
 }
 
 impl std::fmt::Display for LogNormalError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             LogNormalError::LocationInvalid => write!(f, "Location is NaN"),
diff --git a/src/distribution/multinomial.rs b/src/distribution/multinomial.rs
index 4fcaca1a..aca82a2a 100644
--- a/src/distribution/multinomial.rs
+++ b/src/distribution/multinomial.rs
@@ -47,6 +47,7 @@ pub enum MultinomialError {
 }
 
 impl std::fmt::Display for MultinomialError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             MultinomialError::NotEnoughProbabilities => write!(f, "Fewer than two probabilities"),
diff --git a/src/distribution/multivariate_normal.rs b/src/distribution/multivariate_normal.rs
index 0da93cd4..68b8d098 100644
--- a/src/distribution/multivariate_normal.rs
+++ b/src/distribution/multivariate_normal.rs
@@ -127,6 +127,7 @@ pub enum MultivariateNormalError {
 }
 
 impl std::fmt::Display for MultivariateNormalError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             MultivariateNormalError::CovInvalid => {
diff --git a/src/distribution/multivariate_students_t.rs b/src/distribution/multivariate_students_t.rs
index 143237b8..8bcb1d78 100644
--- a/src/distribution/multivariate_students_t.rs
+++ b/src/distribution/multivariate_students_t.rs
@@ -61,6 +61,7 @@ pub enum MultivariateStudentError {
 }
 
 impl std::fmt::Display for MultivariateStudentError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             MultivariateStudentError::ScaleInvalid => {
diff --git a/src/distribution/negative_binomial.rs b/src/distribution/negative_binomial.rs
index a3f4ffed..6ed557be 100644
--- a/src/distribution/negative_binomial.rs
+++ b/src/distribution/negative_binomial.rs
@@ -52,6 +52,7 @@ pub enum NegativeBinomialError {
 }
 
 impl std::fmt::Display for NegativeBinomialError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             NegativeBinomialError::RInvalid => write!(f, "r is NaN or less than zero"),
diff --git a/src/distribution/normal.rs b/src/distribution/normal.rs
index 71f50eda..b536c101 100644
--- a/src/distribution/normal.rs
+++ b/src/distribution/normal.rs
@@ -36,6 +36,7 @@ pub enum NormalError {
 }
 
 impl std::fmt::Display for NormalError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             NormalError::MeanInvalid => write!(f, "Mean is NaN"),
diff --git a/src/distribution/pareto.rs b/src/distribution/pareto.rs
index 06f9e176..886db43b 100644
--- a/src/distribution/pareto.rs
+++ b/src/distribution/pareto.rs
@@ -36,6 +36,7 @@ pub enum ParetoError {
 }
 
 impl std::fmt::Display for ParetoError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             ParetoError::ScaleInvalid => write!(f, "Scale is NaN, zero, or less than zero"),
diff --git a/src/distribution/poisson.rs b/src/distribution/poisson.rs
index 0780cf55..33e8f8a2 100644
--- a/src/distribution/poisson.rs
+++ b/src/distribution/poisson.rs
@@ -32,6 +32,7 @@ pub enum PoissonError {
 }
 
 impl std::fmt::Display for PoissonError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             PoissonError::LambdaInvalid => write!(f, "Lambda is NaN, zero or less than zero"),
diff --git a/src/distribution/students_t.rs b/src/distribution/students_t.rs
index b9543cc1..cc88707f 100644
--- a/src/distribution/students_t.rs
+++ b/src/distribution/students_t.rs
@@ -40,6 +40,7 @@ pub enum StudentsTError {
 }
 
 impl std::fmt::Display for StudentsTError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             StudentsTError::LocationInvalid => write!(f, "Location is NaN"),
diff --git a/src/distribution/triangular.rs b/src/distribution/triangular.rs
index 9115e3c4..eb3cb93d 100644
--- a/src/distribution/triangular.rs
+++ b/src/distribution/triangular.rs
@@ -45,6 +45,7 @@ pub enum TriangularError {
 }
 
 impl std::fmt::Display for TriangularError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             TriangularError::MinInvalid => write!(f, "Minimum is NaN or infinite."),
diff --git a/src/distribution/uniform.rs b/src/distribution/uniform.rs
index 588413cb..55bd7884 100644
--- a/src/distribution/uniform.rs
+++ b/src/distribution/uniform.rs
@@ -40,6 +40,7 @@ pub enum UniformError {
 }
 
 impl std::fmt::Display for UniformError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             UniformError::MinInvalid => write!(f, "Minimum is NaN or infinite"),
diff --git a/src/distribution/weibull.rs b/src/distribution/weibull.rs
index e0d856c5..71aa30ef 100644
--- a/src/distribution/weibull.rs
+++ b/src/distribution/weibull.rs
@@ -39,6 +39,7 @@ pub enum WeibullError {
 }
 
 impl std::fmt::Display for WeibullError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             WeibullError::ShapeInvalid => write!(f, "Shape is NaN, zero or less than zero."),
diff --git a/src/lib.rs b/src/lib.rs
index 56f9b162..7ca3157c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -48,6 +48,7 @@
 #![allow(clippy::excessive_precision)]
 #![allow(clippy::many_single_char_names)]
 #![forbid(unsafe_code)]
+#![cfg_attr(coverage_nightly, feature(coverage_attribute))]
 
 #[macro_use]
 extern crate approx;
diff --git a/src/stats_tests/fisher.rs b/src/stats_tests/fisher.rs
index 31d07173..909b4e7b 100644
--- a/src/stats_tests/fisher.rs
+++ b/src/stats_tests/fisher.rs
@@ -105,6 +105,7 @@ pub enum FishersExactTestError {
 }
 
 impl std::fmt::Display for FishersExactTestError {
+    #[cfg_attr(coverage_nightly, coverage(off))]
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             FishersExactTestError::TableInvalidForHypergeometric(hg_err) => {