diff --git a/autotests/klocalizedstringtest.cpp b/autotests/klocalizedstringtest.cpp
--- a/autotests/klocalizedstringtest.cpp
+++ b/autotests/klocalizedstringtest.cpp
@@ -218,6 +218,12 @@
              QString("   42"));
     QCOMPARE(ki18n("%1").subs(42, -5, 10, QChar('_')).toString(),
              QString("42___"));
+
+    QLocale::setDefault(QLocale(QLocale::French));
+    QCOMPARE(ki18n("%1").subs(4.2, 5, 'f', 2).toString(),
+             QString(" 4,20"));
+
+    QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
     QCOMPARE(ki18n("%1").subs(4.2, 5, 'f', 2).toString(),
              QString(" 4.20"));
 }
diff --git a/src/klocalizedstring.cpp b/src/klocalizedstring.cpp
--- a/src/klocalizedstring.cpp
+++ b/src/klocalizedstring.cpp
@@ -1138,7 +1138,7 @@
 {
     KLocalizedString kls(*this);
     kls.d->checkNumber(std::abs(a));
-    kls.d->arguments.append(QStringLiteral("%1").arg(a, fieldWidth, base, fillChar));
+    kls.d->arguments.append(QStringLiteral("%L1").arg(a, fieldWidth, base, fillChar));
     kls.d->values.append(static_cast<intn>(a));
     return kls;
 }
@@ -1148,7 +1148,7 @@
 {
     KLocalizedString kls(*this);
     kls.d->checkNumber(a);
-    kls.d->arguments.append(QStringLiteral("%1").arg(a, fieldWidth, base, fillChar));
+    kls.d->arguments.append(QStringLiteral("%L1").arg(a, fieldWidth, base, fillChar));
     kls.d->values.append(static_cast<uintn>(a));
     return kls;
 }
@@ -1158,7 +1158,7 @@
 {
     KLocalizedString kls(*this);
     kls.d->checkNumber(std::abs(a));
-    kls.d->arguments.append(QStringLiteral("%1").arg(a, fieldWidth, base, fillChar));
+    kls.d->arguments.append(QStringLiteral("%L1").arg(a, fieldWidth, base, fillChar));
     kls.d->values.append(static_cast<intn>(a));
     return kls;
 }
@@ -1168,7 +1168,7 @@
 {
     KLocalizedString kls(*this);
     kls.d->checkNumber(a);
-    kls.d->arguments.append(QStringLiteral("%1").arg(a, fieldWidth, base, fillChar));
+    kls.d->arguments.append(QStringLiteral("%L1").arg(a, fieldWidth, base, fillChar));
     kls.d->values.append(static_cast<uintn>(a));
     return kls;
 }
@@ -1178,7 +1178,7 @@
 {
     KLocalizedString kls(*this);
     kls.d->checkNumber(qAbs(a));
-    kls.d->arguments.append(QStringLiteral("%1").arg(a, fieldWidth, base, fillChar));
+    kls.d->arguments.append(QStringLiteral("%L1").arg(a, fieldWidth, base, fillChar));
     kls.d->values.append(static_cast<intn>(a));
     return kls;
 }
@@ -1188,7 +1188,7 @@
 {
     KLocalizedString kls(*this);
     kls.d->checkNumber(a);
-    kls.d->arguments.append(QStringLiteral("%1").arg(a, fieldWidth, base, fillChar));
+    kls.d->arguments.append(QStringLiteral("%L1").arg(a, fieldWidth, base, fillChar));
     kls.d->values.append(static_cast<uintn>(a));
     return kls;
 }
@@ -1198,7 +1198,7 @@
                                         QChar fillChar) const
 {
     KLocalizedString kls(*this);
-    kls.d->arguments.append(QStringLiteral("%1").arg(a, fieldWidth, format, precision, fillChar));
+    kls.d->arguments.append(QStringLiteral("%L1").arg(a, fieldWidth, format, precision, fillChar));
     kls.d->values.append(static_cast<realn>(a));
     return kls;
 }