diff --git a/samples/write-test.cpp b/samples/write-test.cpp
index d62c66da..16ef3bae 100644
--- a/samples/write-test.cpp
+++ b/samples/write-test.cpp
@@ -128,7 +128,7 @@ void testCase(const std::string& file1, const std::string& file2, const std::str
   std::cerr << "---> Modifying Exif data\n";
   auto pos = ed1.findKey(ek);
   if (pos == ed1.end()) {
-    throw Error(ErrorCode::kerErrorMessage, "Metadatum with key = " + ek.key() + " not found");
+    throw Error(ErrorCode::kerErrorMessage, "Metadatum with key = ", ek.key(), " not found");
   }
   pos->setValue(value);
 
diff --git a/src/canonmn_int.cpp b/src/canonmn_int.cpp
index 3de6946f..704ae0ca 100644
--- a/src/canonmn_int.cpp
+++ b/src/canonmn_int.cpp
@@ -2911,7 +2911,7 @@ std::ostream& printCsLensTypeByMetadata(std::ostream& os, const Value& value, co
     if (!std::regex_search(label, base_match, lens_regex)) {
       // this should never happen, as it would indicate the lens is specified incorrectly
       // in the CanonCsLensType array
-      throw Error(ErrorCode::kerErrorMessage, std::string("Lens regex didn't match for: ") + std::string(label));
+      throw Error(ErrorCode::kerErrorMessage, "Lens regex didn't match for: ", label);
     }
 
     auto tc = base_match[5].length() > 0 ? std::stof(base_match[5].str()) : 1.f;
diff --git a/src/preview.cpp b/src/preview.cpp
index 6a0a58f7..21ae651e 100644
--- a/src/preview.cpp
+++ b/src/preview.cpp
@@ -425,7 +425,7 @@ DataBuf LoaderNative::getData() const {
     }
     return {record + sizeHdr + 28, sizeData - 28};
   }
-  throw Error(ErrorCode::kerErrorMessage, "Invalid native preview filter: " + nativePreview_.filter_);
+  throw Error(ErrorCode::kerErrorMessage, "Invalid native preview filter: ", nativePreview_.filter_);
 }
 
 bool LoaderNative::readDimensions() {
diff --git a/src/tags_int.hpp b/src/tags_int.hpp
index 33ec7989..6e6e7f2d 100644
--- a/src/tags_int.hpp
+++ b/src/tags_int.hpp
@@ -231,7 +231,7 @@ std::ostream& printTagBitmask(std::ostream& os, const Value& value, const ExifDa
 template <size_t N, const TagDetailsBitlistSorted (&array)[N]>
 std::ostream& printTagBitlistAllLE(std::ostream& os, const Value& value, const ExifData*) {
   if constexpr (N == 0)
-    throw Error(ErrorCode::kerErrorMessage, std::string("Passed zero length TagDetailsBitlistSorted"));
+    throw Error(ErrorCode::kerErrorMessage, "Passed zero length TagDetailsBitlistSorted");
 
   uint32_t vN = 0;
   uint32_t currentVNBit = 0;