diff -rupN exiv2-0.27.1/include/exiv2/error.hpp exiv2-0.27.1-new/include/exiv2/error.hpp
--- exiv2-0.27.1/include/exiv2/error.hpp	2019-04-25 22:18:55.000000000 +0200
+++ exiv2-0.27.1-new/include/exiv2/error.hpp	2019-04-29 11:27:05.873234423 +0200
@@ -179,6 +179,9 @@ namespace Exiv2 {
         virtual ~AnyError() throw();
         ///@brief  Return the error code.
         virtual int code() const throw() =0;
+
+    protected:
+        std::string localizedErrMsg(int code);
     };
 
     //! %AnyError output operator
@@ -304,7 +307,7 @@ namespace Exiv2 {
         //! @name Manipulators
         //@{
         //! Assemble the error message from the arguments
-        EXIV2API void setMsg();
+        void setMsg();
         //@}
 
         // DATA
@@ -390,6 +393,77 @@ namespace Exiv2 {
     }
 #endif
 
+    template<>
+    inline void BasicError<char>::setMsg()
+    {
+        std::string msg = localizedErrMsg(code_);
+        std::string::size_type pos;
+        pos = msg.find("%0");
+        if (pos != std::string::npos) {
+            msg.replace(pos, 2, toString(code_));
+        }
+        if (count_ > 0) {
+            pos = msg.find("%1");
+            if (pos != std::string::npos) {
+                msg.replace(pos, 2, arg1_);
+            }
+        }
+        if (count_ > 1) {
+            pos = msg.find("%2");
+            if (pos != std::string::npos) {
+                msg.replace(pos, 2, arg2_);
+            }
+        }
+        if (count_ > 2) {
+            pos = msg.find("%3");
+            if (pos != std::string::npos) {
+                msg.replace(pos, 2, arg3_);
+            }
+        }
+        msg_ = msg;
+#ifdef EXV_UNICODE_PATH
+        wmsg_ = s2ws(msg);
+#endif
+    }
+#ifdef __APPLE__
+    template class EXIV2API BasicError<char>;
+#endif
+
+#ifdef EXV_UNICODE_PATH
+    template<>
+    inline void BasicError<wchar_t>::setMsg()
+    {
+        std::string s = localizedErrMsg(code_);
+        std::wstring wmsg(s.begin(), s.end());
+        std::wstring::size_type pos;
+        pos = wmsg.find(L"%0");
+        if (pos != std::wstring::npos) {
+            wmsg.replace(pos, 2, toBasicString<wchar_t>(code_));
+        }
+        if (count_ > 0) {
+            pos = wmsg.find(L"%1");
+            if (pos != std::wstring::npos) {
+                wmsg.replace(pos, 2, arg1_);
+            }
+        }
+        if (count_ > 1) {
+            pos = wmsg.find(L"%2");
+            if (pos != std::wstring::npos) {
+                wmsg.replace(pos, 2, arg2_);
+            }
+        }
+        if (count_ > 2) {
+            pos = wmsg.find(L"%3");
+            if (pos != std::wstring::npos) {
+                wmsg.replace(pos, 2, arg3_);
+            }
+        }
+        wmsg_ = wmsg;
+        msg_ = ws2s(wmsg);
+    }
+    template class EXIV2API BasicError<wchar_t>;
+#endif
+
 #ifdef _MSC_VER
 # pragma warning( default : 4275 )
 #endif
diff -rupN exiv2-0.27.1/src/error.cpp exiv2-0.27.1-new/src/error.cpp
--- exiv2-0.27.1/src/error.cpp	2019-04-25 22:18:55.000000000 +0200
+++ exiv2-0.27.1-new/src/error.cpp	2019-04-29 11:27:05.873234423 +0200
@@ -224,76 +224,10 @@ namespace Exiv2 {
     {
     }
 
-    template<>
-    void BasicError<char>::setMsg()
+    std::string AnyError::localizedErrMsg(int code)
     {
-        std::string msg = _(errMsg(code_));
-        std::string::size_type pos;
-        pos = msg.find("%0");
-        if (pos != std::string::npos) {
-            msg.replace(pos, 2, toString(code_));
-        }
-        if (count_ > 0) {
-            pos = msg.find("%1");
-            if (pos != std::string::npos) {
-                msg.replace(pos, 2, arg1_);
-            }
-        }
-        if (count_ > 1) {
-            pos = msg.find("%2");
-            if (pos != std::string::npos) {
-                msg.replace(pos, 2, arg2_);
-            }
-        }
-        if (count_ > 2) {
-            pos = msg.find("%3");
-            if (pos != std::string::npos) {
-                msg.replace(pos, 2, arg3_);
-            }
-        }
-        msg_ = msg;
-#ifdef EXV_UNICODE_PATH
-        wmsg_ = s2ws(msg);
-#endif
+        return _(errMsg(code));
     }
-#ifdef __APPLE__
-    template class EXIV2API BasicError<char>;
-#endif
-
-#ifdef EXV_UNICODE_PATH
-    template<>
-    void BasicError<wchar_t>::setMsg()
-    {
-        std::string s = _(errMsg(code_));
-        std::wstring wmsg(s.begin(), s.end());
-        std::wstring::size_type pos;
-        pos = wmsg.find(L"%0");
-        if (pos != std::wstring::npos) {
-            wmsg.replace(pos, 2, toBasicString<wchar_t>(code_));
-        }
-        if (count_ > 0) {
-            pos = wmsg.find(L"%1");
-            if (pos != std::wstring::npos) {
-                wmsg.replace(pos, 2, arg1_);
-            }
-        }
-        if (count_ > 1) {
-            pos = wmsg.find(L"%2");
-            if (pos != std::wstring::npos) {
-                wmsg.replace(pos, 2, arg2_);
-            }
-        }
-        if (count_ > 2) {
-            pos = wmsg.find(L"%3");
-            if (pos != std::wstring::npos) {
-                wmsg.replace(pos, 2, arg3_);
-            }
-        }
-        wmsg_ = wmsg;
-        msg_ = ws2s(wmsg);
-    }
-    template class EXIV2API BasicError<wchar_t>;
-#endif
 
     const char* errMsg(int code)
     {