diff --git a/src/gui/opengl/qopenglprogrambinarycache.cpp b/src/gui/opengl/qopenglprogrambinarycache.cpp
index af48cdacc79..40237b9935e 100644
--- a/src/gui/opengl/qopenglprogrambinarycache.cpp
+++ b/src/gui/opengl/qopenglprogrambinarycache.cpp
@@ -263,6 +263,7 @@ public:
 
 bool QOpenGLProgramBinaryCache::load(const QByteArray &cacheKey, uint programId)
 {
+    QMutexLocker lock(&m_mutex);
     if (m_memCache.contains(cacheKey)) {
         const MemCacheEntry *e = m_memCache[cacheKey];
         return setProgramBinary(programId, e->format, e->blob.constData(), e->blob.size());
@@ -401,6 +402,7 @@ void QOpenGLProgramBinaryCache::save(const QByteArray &cacheKey, uint programId)
     GLint outSize = 0;
 #if defined(QT_OPENGL_ES_2)
     if (context->isOpenGLES() && context->format().majorVersion() < 3) {
+        QMutexLocker lock(&m_mutex);
         initializeProgramBinaryOES(context);
         getProgramBinaryOES(programId, blobSize, &outSize, &blobFormat, p);
     } else
diff --git a/src/gui/opengl/qopenglprogrambinarycache_p.h b/src/gui/opengl/qopenglprogrambinarycache_p.h
index 9fade08e66d..e181a6ab814 100644
--- a/src/gui/opengl/qopenglprogrambinarycache_p.h
+++ b/src/gui/opengl/qopenglprogrambinarycache_p.h
@@ -54,6 +54,7 @@
 #include <QtGui/qtguiglobal.h>
 #include <QtGui/qopenglshaderprogram.h>
 #include <QtCore/qcache.h>
+#include <QtCore/qmutex.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -99,6 +100,7 @@ private:
     void initializeProgramBinaryOES(QOpenGLContext *context);
     bool m_programBinaryOESInitialized = false;
 #endif
+    QMutex m_mutex;
 };
 
 QT_END_NAMESPACE