diff --git a/src/corelib/thread/qreadwritelock.cpp b/src/corelib/thread/qreadwritelock.cpp
index 894e8524943..f22f3dab409 100644
--- a/src/corelib/thread/qreadwritelock.cpp
+++ b/src/corelib/thread/qreadwritelock.cpp
@@ -50,6 +50,8 @@
 #include "private/qfreelist_p.h"
 #include "private/qlocking_p.h"
 
+#include <algorithm>
+
 QT_BEGIN_NAMESPACE
 
 /*
@@ -534,6 +536,11 @@ void QReadWriteLockPrivate::unlock()
         readerCond.wakeAll();
 }
 
+static auto handleEquals(Qt::HANDLE handle)
+{
+    return [handle](QReadWriteLockPrivate::Reader reader) { return reader.handle == handle; };
+}
+
 bool QReadWriteLockPrivate::recursiveLockForRead(int timeout)
 {
     Q_ASSERT(recursive);
@@ -541,16 +548,18 @@ bool QReadWriteLockPrivate::recursiveLockForRead(int timeout)
 
     Qt::HANDLE self = QThread::currentThreadId();
 
-    auto it = currentReaders.find(self);
+    auto it = std::find_if(currentReaders.begin(), currentReaders.end(),
+                           handleEquals(self));
     if (it != currentReaders.end()) {
-        ++it.value();
+        ++it->recursionLevel;
         return true;
     }
 
     if (!lockForRead(timeout))
         return false;
 
-    currentReaders.insert(self, 1);
+    Reader r = {self, 1};
+    currentReaders.append(std::move(r));
     return true;
 }
 
@@ -583,12 +592,13 @@ void QReadWriteLockPrivate::recursiveUnlock()
             return;
         currentWriter = nullptr;
     } else {
-        auto it = currentReaders.find(self);
+        auto it = std::find_if(currentReaders.begin(), currentReaders.end(),
+                               handleEquals(self));
         if (it == currentReaders.end()) {
             qWarning("QReadWriteLock::unlock: unlocking from a thread that did not lock");
             return;
         } else {
-            if (--it.value() <= 0) {
+            if (--it->recursionLevel <= 0) {
                 currentReaders.erase(it);
                 readerCount--;
             }
diff --git a/src/corelib/thread/qreadwritelock_p.h b/src/corelib/thread/qreadwritelock_p.h
index a4d002b7f2a..1adbce6658c 100644
--- a/src/corelib/thread/qreadwritelock_p.h
+++ b/src/corelib/thread/qreadwritelock_p.h
@@ -53,7 +53,7 @@
 //
 
 #include <QtCore/private/qglobal_p.h>
-#include <QtCore/qhash.h>
+#include <QtCore/qvarlengtharray.h>
 #include <QtCore/qwaitcondition.h>
 
 QT_REQUIRE_CONFIG(thread);
@@ -87,13 +87,20 @@ public:
 
     // Recusive mutex handling
     Qt::HANDLE currentWriter = {};
-    QHash<Qt::HANDLE, int> currentReaders;
+
+    struct Reader {
+        Qt::HANDLE handle;
+        int recursionLevel;
+    };
+
+    QVarLengthArray<Reader, 16> currentReaders;
 
     // called with the mutex unlocked
     bool recursiveLockForWrite(int timeout);
     bool recursiveLockForRead(int timeout);
     void recursiveUnlock();
 };
+Q_DECLARE_TYPEINFO(QReadWriteLockPrivate::Reader, Q_PRIMITIVE_TYPE);
 
 QT_END_NAMESPACE