diff --git a/src/portable_archive/portable_iarchive.hpp b/src/portable_archive/portable_iarchive.hpp
index 85668b45..89be7cd4 100644
--- a/src/portable_archive/portable_iarchive.hpp
+++ b/src/portable_archive/portable_iarchive.hpp
@@ -194,8 +194,9 @@ class portable_iarchive : public portable_iprimitive
 		// after reading the note above you still might decide to
 		// deactivate this static assert and try if it works out.
 		typename traits::bits bits;
-		static_assert(sizeof(bits) == sizeof(T));
-		static_assert(std::numeric_limits<T>::is_iec559);
+		static_assert(sizeof(bits) == sizeof(T), "mismatching type sizes");
+		static_assert(std::numeric_limits<T>::is_iec559,
+			"floating point type does not conform to IEC 559 (IEEE 754)");
 
 		load(bits);
 		traits::set_bits(t, bits);
diff --git a/src/sample.cpp b/src/sample.cpp
index 706c6b8f..b95521b0 100644
--- a/src/sample.cpp
+++ b/src/sample.cpp
@@ -356,7 +356,7 @@ void lsl::sample::serialize(eos::portable_iarchive &ar, const uint32_t archive_v
 template <typename T> void test_pattern(T *data, uint32_t num_channels, int offset) {
 	for (std::size_t k = 0; k < num_channels; k++) {
 		std::size_t val = k + static_cast<std::size_t>(offset);
-		if (std::is_integral_v<T>) val %= static_cast<std::size_t>(std::numeric_limits<T>::max());
+		if (std::is_integral<T>::value) val %= static_cast<std::size_t>(std::numeric_limits<T>::max());
 		data[k] = (k % 2 == 0) ? static_cast<T>(val) : -static_cast<T>(val);
 	}
 }