diff --git a/libgnucash/engine/gnc-numeric.cpp b/libgnucash/engine/gnc-numeric.cpp
index 0fc47d5687..3d540056b8 100644
--- a/libgnucash/engine/gnc-numeric.cpp
+++ b/libgnucash/engine/gnc-numeric.cpp
@@ -1303,6 +1303,18 @@ main(int argc, char ** argv)
 }
 #endif
 
+
+std::ostream&
+operator<<(std::ostream& s, GncNumeric n)
+{
+    std::basic_ostringstream<wchar_t> ss;
+    ss.imbue(s.getloc());
+    ss << n;
+    std::wstring_convert<std::codecvt_utf8<wchar_t>> make_utf8;
+    s << make_utf8.to_bytes(ss.str());
+    return s;
+}
+
 const char* gnc_numeric_errorCode_to_string(GNCNumericErrorCode error_code)
 {
     switch (error_code)
diff --git a/libgnucash/engine/gnc-numeric.hpp b/libgnucash/engine/gnc-numeric.hpp
index d9ff3d7a75..a22f89bd43 100644
--- a/libgnucash/engine/gnc-numeric.hpp
+++ b/libgnucash/engine/gnc-numeric.hpp
@@ -27,6 +27,7 @@
 #include <iostream>
 #include <locale>
 #include <typeinfo> // For std::bad_cast exception
+#include <codecvt> // UTF-8 <--> UTF16 conversion
 #include "gnc-rational-rounding.hpp"
 
 class GncRational;
@@ -339,6 +340,7 @@ inline GncNumeric operator/(int64_t a, GncNumeric b)
  * decimal if the denominator is a multiple of 10, otherwise as
  * "numerator/denominator".
  */
+std::ostream& operator<<(std::ostream&, GncNumeric);
 
 /* Implementation adapted from "The C++ Standard Library, Second Edition" by
  * Nicolai M. Josuttis, Addison-Wesley, 2012, ISBN 978-0-321-62321-8.
@@ -349,10 +351,10 @@ std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>&
     std::basic_ostringstream<charT, traits> ss;
     std::locale loc = s.getloc();
     ss.imbue(loc);
-    char dec_pt = '.';
+    auto dec_pt = static_cast<charT>('.');
     try
     {
-        dec_pt = std::use_facet<std::numpunct<char>>(loc).decimal_point();
+        dec_pt = std::use_facet<std::numpunct<charT>>(loc).decimal_point();
     }
     catch(const std::bad_cast& err) {} //Don't do anything, num_sep is already set.
 
@@ -369,7 +371,6 @@ std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>&
     return s;
 }
 
-
 /**
  * std::stream input operator.
  *
@@ -386,7 +387,7 @@ std::basic_ostream<charT, traits>& operator<<(std::basic_ostream<charT, traits>&
 template <typename charT, typename traits>
 std::basic_istream<charT, traits>& operator>>(std::basic_istream<charT, traits>& s, GncNumeric& n)
 {
-    std::string instr;
+    std::basic_string<charT, traits> instr;
     s >> instr;
     if (s)
         n = GncNumeric(instr, true);
diff --git a/libgnucash/engine/test/gtest-gnc-numeric.cpp b/libgnucash/engine/test/gtest-gnc-numeric.cpp
index 82d6b8fa4a..8326071f41 100644
--- a/libgnucash/engine/test/gtest-gnc-numeric.cpp
+++ b/libgnucash/engine/test/gtest-gnc-numeric.cpp
@@ -213,10 +213,15 @@ TEST(gncnumeric_stream, output_stream)
     EXPECT_EQ("123/456", output.str());
     try
     {
-        output.imbue(std::locale("fr_FR.utf8"));
+        auto loc = std::locale("fr_FR.utf8");
+        auto thou_sep = std::use_facet<std::numpunct<wchar_t>>(loc).thousands_sep();
+        output.imbue(loc);
         output.str("");
         output << simple_int;
-        EXPECT_EQ("123 456", output.str());
+        if (thou_sep == L' ')
+            EXPECT_EQ("123 456", output.str());
+        else
+            EXPECT_EQ("123\xe2\x80\xaf""456", output.str());
     }
     catch (std::runtime_error)
     {