diff --git a/linphone-desktop/src/components/camera/MSFunctions.hpp b/linphone-desktop/src/components/camera/MSFunctions.hpp
index 7320092a7..9b1fc7624 100644
--- a/linphone-desktop/src/components/camera/MSFunctions.hpp
+++ b/linphone-desktop/src/components/camera/MSFunctions.hpp
@@ -4,11 +4,11 @@
 #include <QOpenGLFunctions>
 
 #define GL_CALL(CALL) \
-  Q_ASSERT(QOpenGLContext::currentContext()->functions() == m_instance->m_q_functions); \
+  Q_ASSERT(QOpenGLContext::currentContext()->functions() == m_instance->m_q_functions && m_instance->m_q_functions != NULL); \
   m_instance->m_q_functions->CALL;
 
 #define GL_CALL_RET(CALL) \
-  Q_ASSERT(QOpenGLContext::currentContext()->functions() == m_instance->m_q_functions); \
+  Q_ASSERT(QOpenGLContext::currentContext()->functions() == m_instance->m_q_functions && m_instance->m_q_functions != NULL); \
   return m_instance->m_q_functions->CALL;
 
 // =============================================================================
@@ -193,4 +193,7 @@ private:
   static MSFunctions *m_instance;
 };
 
+#undef GL_CALL
+#undef GL_CALL_RET
+
 #endif // MS_FUNCTIONS_H_