diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index 5f151ffbd67..0e3bcf914f0 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -10996,8 +10996,14 @@ qsizetype QtPrivate::count(QStringView haystack, const QRegularExpression &re)
         QRegularExpressionMatch match = re.matchView(haystack, index + 1);
         if (!match.hasMatch())
             break;
-        index = match.capturedStart();
         count++;
+
+        // Search again, from the next character after the beginning of this
+        // capture. If the capture starts with a surrogate pair, both together
+        // count as "one character".
+        index = match.capturedStart();
+        if (index < len && haystack[index].isHighSurrogate())
+            ++index;
     }
     return count;
 }
diff --git a/tests/auto/corelib/text/qstring/tst_qstring.cpp b/tests/auto/corelib/text/qstring/tst_qstring.cpp
index aec2d2897a4..701a33a2635 100644
--- a/tests/auto/corelib/text/qstring/tst_qstring.cpp
+++ b/tests/auto/corelib/text/qstring/tst_qstring.cpp
@@ -2041,6 +2041,21 @@ void tst_QString::count()
     QTest::ignoreMessage(QtWarningMsg, ignoreMessagePattern);
     QCOMPARE(emptyStr.count(QRegularExpression("invalid regex\\")), 0);
 #endif
+
+    QString nonBmpString = u8"\U00010000\U00010000abc\U00010000";
+    QCOMPARE(nonBmpString.count(u"\U00010000"), 3);
+#if QT_CONFIG(regularexpression)
+    QCOMPARE(nonBmpString.count(QRegularExpression(u8"\U00010000")), 3);
+    QCOMPARE(nonBmpString.count(QRegularExpression(u8"\U00010000a?")), 3);
+    QCOMPARE(nonBmpString.count(QRegularExpression(u8"\U00010000a")), 1);
+    QCOMPARE(nonBmpString.count(QRegularExpression(".")), 6);
+
+    // can't search for unpaired surrogates
+    QTest::ignoreMessage(QtWarningMsg, ignoreMessagePattern);
+    QCOMPARE(nonBmpString.count(QRegularExpression(QChar(0xd800))), 0);
+    QTest::ignoreMessage(QtWarningMsg, ignoreMessagePattern);
+    QCOMPARE(nonBmpString.count(QRegularExpression(QChar(0xdc00))), 0);
+#endif
 }
 
 void tst_QString::contains()