diff --git a/src/gui/util/qvalidator.cpp b/src/gui/util/qvalidator.cpp
index b968592c01..21641a76b4 100644
--- a/src/gui/util/qvalidator.cpp
+++ b/src/gui/util/qvalidator.cpp
@@ -693,8 +693,9 @@ QValidator::State QDoubleValidatorPrivate::validateWithLocale(QString &input, QL
 
     if (notation == QDoubleValidator::StandardNotation) {
         double max = qMax(qAbs(q->b), qAbs(q->t));
-        if (max < double(LLONG_MAX)) {
-            qlonglong n = pow10(numDigits(qlonglong(max)));
+        qlonglong v;
+        if (convertDoubleTo(max, &v)) {
+            qlonglong n = pow10(numDigits(v));
             // In order to get the highest possible number in the intermediate
             // range we need to get 10 to the power of the number of digits
             // after the decimal's and subtract that from the top number.