diff --git a/include/boost/histogram/utility/binomial_proportion_interval.hpp b/include/boost/histogram/utility/binomial_proportion_interval.hpp
index d085f3ed..caa883c4 100644
--- a/include/boost/histogram/utility/binomial_proportion_interval.hpp
+++ b/include/boost/histogram/utility/binomial_proportion_interval.hpp
@@ -61,7 +61,7 @@ class confidence_level;
 class deviation {
 public:
   /// constructor from units of standard deviations
-  explicit deviation(double d) noexcept : d_{d} {
+  explicit deviation(double d) : d_{d} {
     if (d <= 0)
       BOOST_THROW_EXCEPTION(std::invalid_argument("scaling factor must be positive"));
   }
@@ -93,7 +93,7 @@ private:
 class confidence_level {
 public:
   /// constructor from confidence level (a probability)
-  explicit confidence_level(double cl) noexcept : cl_{cl} {
+  explicit confidence_level(double cl) : cl_{cl} {
     if (cl <= 0 || cl >= 1)
       BOOST_THROW_EXCEPTION(std::invalid_argument("0 < cl < 1 is required"));
   }
diff --git a/test/accumulators_fraction_test.cpp b/test/accumulators_fraction_test.cpp
index 97cdfb77..52885b76 100644
--- a/test/accumulators_fraction_test.cpp
+++ b/test/accumulators_fraction_test.cpp
@@ -45,6 +45,7 @@ void run_tests() {
     BOOST_TEST_EQ(f.successes(), 1);
     BOOST_TEST_EQ(f.failures(), 1);
     BOOST_TEST_EQ(str(f), "fraction(1, 1)"s);
+    BOOST_TEST_EQ(str(f, 20), "fraction(1, 1)      "s);
   }
 
   {
diff --git a/test/utility_binomial_proportion_interval_test.cpp b/test/utility_binomial_proportion_interval_test.cpp
index 00ef6f7c..1a666fe6 100644
--- a/test/utility_binomial_proportion_interval_test.cpp
+++ b/test/utility_binomial_proportion_interval_test.cpp
@@ -26,5 +26,13 @@ int main() {
     BOOST_TEST_IS_CLOSE(static_cast<double>(deviation(cl3)), 3, 1e-8);
   }
 
+  // invalid values
+  {
+    BOOST_TEST_THROWS((void)deviation{-0.5}, std::invalid_argument);
+    BOOST_TEST_THROWS((void)confidence_level{-0.1}, std::invalid_argument);
+    BOOST_TEST_THROWS((void)confidence_level{0}, std::invalid_argument);
+    BOOST_TEST_THROWS((void)confidence_level{1.1}, std::invalid_argument);
+  }
+
   return boost::report_errors();
 }
diff --git a/tools/cov.py b/tools/cov.py
index 84cb3897..4280047c 100755
--- a/tools/cov.py
+++ b/tools/cov.py
@@ -16,7 +16,7 @@ from pathlib import Path
 import os
 import sys
 
-LCOV_VERSION = "1.15"
+LCOV_VERSION = "1.16"
 
 gcov = os.environ.get("GCOV", "gcov")