diff --git a/src/vk_mem_alloc.h b/src/vk_mem_alloc.h
index d0a5896..73811d1 100644
--- a/src/vk_mem_alloc.h
+++ b/src/vk_mem_alloc.h
@@ -6401,7 +6401,7 @@
     {
         if(m_UnmapPersistentlyMappedMemoryCounter == 0)
         {
-            res = (*this->GetVulkanFunctions().vkMapMemory)(
+            res = (*m_VulkanFunctions.vkMapMemory)(
                 m_hDevice,
                 hMemory,
                 0,
@@ -7021,7 +7021,7 @@
     
     if(allocation->GetMappedData() != VMA_NULL)
     {
-        (*this->GetVulkanFunctions().vkUnmapMemory)(m_hDevice, hMemory);
+        (*m_VulkanFunctions.vkUnmapMemory)(m_hDevice, hMemory);
     }
     
     FreeVulkanMemory(memTypeIndex, allocation->GetSize(), hMemory);