diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp
index b50d5901e0c..7a8623dc254 100644
--- a/src/corelib/text/qbytearray.cpp
+++ b/src/corelib/text/qbytearray.cpp
@@ -4082,7 +4082,8 @@ double QByteArray::toDouble(bool *ok) const
 
 auto QtPrivate::toDouble(QByteArrayView a) noexcept -> ParsedNumber<double>
 {
-    auto r = qt_asciiToDouble(a.data(), a.size(), WhitespacesAllowed);
+    a = a.trimmed();
+    auto r = qt_asciiToDouble(a.data(), a.size());
     if (r.ok())
         return ParsedNumber{r.result};
     else
diff --git a/tests/auto/corelib/text/qbytearrayapisymmetry/tst_qbytearrayapisymmetry.cpp b/tests/auto/corelib/text/qbytearrayapisymmetry/tst_qbytearrayapisymmetry.cpp
index f03086342ce..f8343c8806b 100644
--- a/tests/auto/corelib/text/qbytearrayapisymmetry/tst_qbytearrayapisymmetry.cpp
+++ b/tests/auto/corelib/text/qbytearrayapisymmetry/tst_qbytearrayapisymmetry.cpp
@@ -1497,9 +1497,18 @@ template <typename ByteArray> void tst_QByteArrayApiSymmetry::toFloat() const
     QCOMPARE(ByteArray().toFloat(&ok), 0.0f);
     QVERIFY(!ok);
 
+    ok = true;
     QCOMPARE(ByteArray("").toFloat(&ok), 0.0f);
     QVERIFY(!ok);
 
+    ok = true;
+    QCOMPARE(ByteArray(" ").toFloat(&ok), 0.0f);
+    QVERIFY(!ok);
+
+    ok = true;
+    QCOMPARE(ByteArray("  ").toFloat(&ok), 0.0f);
+    QVERIFY(!ok);
+
     // NB: floats < 1e-6 are zero as far as QCOMPARE() is concerned !
     const char data[] = "0.0000931322574615478515625";
     const float expectedValue = 9.31322574615478515625e-5f;
@@ -1523,6 +1532,8 @@ void tst_QByteArrayApiSymmetry::toDouble_data() const
 
     QTest::newRow("null") << QByteArray() << 0.0 << false;
     QTest::newRow("empty") << QByteArray("") << 0.0 << false;
+    QTest::newRow("space-only") << QByteArray(" ") << 0.0 << false;
+    QTest::newRow("spaces-only") << QByteArray("  ") << 0.0 << false;
 
     QTest::newRow("decimal") << QByteArray("1.2345") << 1.2345 << true;
     QTest::newRow("exponent lowercase") << QByteArray("1.2345e+01") << 12.345 << true;
diff --git a/tests/auto/corelib/text/qstring/tst_qstring.cpp b/tests/auto/corelib/text/qstring/tst_qstring.cpp
index 80f83519571..cfc0ec1cc07 100644
--- a/tests/auto/corelib/text/qstring/tst_qstring.cpp
+++ b/tests/auto/corelib/text/qstring/tst_qstring.cpp
@@ -7622,8 +7622,10 @@ void tst_QString::double_conversion_data()
 
     // The bad...
 
+    QTest::newRow("C null")          << QString()       << false << 0.0;
     QTest::newRow("C empty")         << u""_s           << false << 0.0;
-    QTest::newRow("C null")          << QString()             << false << 0.0;
+    QTest::newRow("C space")         << u" "_s          << false << 0.0;
+    QTest::newRow("C spaces")        << u"  "_s         << false << 0.0;
     QTest::newRow("C .")             << u"."_s          << false << 0.0;
     QTest::newRow("C 1e")            << u"1e"_s         << false << 0.0;
     QTest::newRow("C 1,")            << u"1,"_s         << false << 0.0;