diff --git a/RenderSystems/Vulkan/src/Vao/OgreVulkanVaoManager.cpp b/RenderSystems/Vulkan/src/Vao/OgreVulkanVaoManager.cpp
index 77a47b65a7..7f19b21204 100644
--- a/RenderSystems/Vulkan/src/Vao/OgreVulkanVaoManager.cpp
+++ b/RenderSystems/Vulkan/src/Vao/OgreVulkanVaoManager.cpp
@@ -186,7 +186,7 @@ namespace Ogre
             if( itor != params->end() )
             {
                 mDelayedBlocksFlushThreshold = static_cast<size_t>(
-                    StringConverter::parseUnsignedLong( itor->second, mDelayedBlocksFlushThreshold ) );
+                    StringConverter::parseSizeT( itor->second, mDelayedBlocksFlushThreshold ) );
             }
         }
     }