diff --git a/src/canonmn_int.cpp b/src/canonmn_int.cpp
index 8292b0ad7a..ef8418dbc9 100644
--- a/src/canonmn_int.cpp
+++ b/src/canonmn_int.cpp
@@ -2967,7 +2967,7 @@ std::ostream& CanonMakerNote::printSi0x0003(std::ostream& os, const Value& value
     // see also printSi0x0017
     std::ostringstream oss;
     oss.copyfmt(os);
-    auto res = static_cast<int>(100.0 * (static_cast<short>(value.toInt64()) / 32.0 + 5.0) + 0.5);
+    auto res = std::lround(100.0 * (static_cast<short>(value.toInt64()) / 32.0 + 5.0));
     os << std::fixed << std::setprecision(2) << res / 100.0;
     os.copyfmt(oss);
   }
diff --git a/src/nikonmn_int.cpp b/src/nikonmn_int.cpp
index d191d3dd07..2e0ee50778 100644
--- a/src/nikonmn_int.cpp
+++ b/src/nikonmn_int.cpp
@@ -1731,8 +1731,8 @@ const TagInfo* Nikon3MakerNote::tagListLd4() {
 }
 
 std::ostream& Nikon3MakerNote::printIiIso(std::ostream& os, const Value& value, const ExifData*) {
-  double v = 100 * exp((value.toInt64() / 12.0 - 5) * log(2.0));
-  return os << static_cast<int>(v + 0.5);
+  auto v = std::lround(100.0f * std::exp((value.toInt64() / 12.0f - 5) * std::log(2.0f)));
+  return os << v;
 }
 
 std::ostream& Nikon3MakerNote::print0x0002(std::ostream& os, const Value& value, const ExifData*) {
diff --git a/src/tiffcomposite_int.cpp b/src/tiffcomposite_int.cpp
index b2eb6b8715..56c04f8de1 100644
--- a/src/tiffcomposite_int.cpp
+++ b/src/tiffcomposite_int.cpp
@@ -784,7 +784,7 @@ size_t TiffBinaryArray::doCount() const {
     typeSize = 1;
   }
 
-  return static_cast<size_t>(static_cast<double>(size()) / typeSize + 0.5);
+  return std::lround(static_cast<double>(size()) / typeSize);
 }
 
 size_t TiffBinaryElement::doCount() const {